Method for controlling electronic program information and apparatus for receiving the electronic program information

ABSTRACT

A data transmission system for minimizing the number of errors during Tx/Rx times of digital data under mobile environments, and a data processing method for the same are disclosed. The system additionally codes digital data, and transmits the resultant coded data. As a result, the program information has a strong resistance to noise and channel variation, and can quickly cope with the rapid channel variation.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. §119, this application claims the benefit of earlier filing date and right of priority to Korean Patent Application No. 10-2007-0034083, filed on Apr. 6, 2007, and also claims the benefit of U.S. Provisional Application Nos. 60/911,055, filed on Apr. 10, 2007, and 60/947,984 filed on Jul. 4, 2007, the contents of which are all hereby incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for transmitting/receiving digital data including electronic program information.

2. Discussion of the Related Art

The Vestigial Sideband (VSB) transmission mode, which is adopted as the standard for digital broadcasting in North America and the Republic of Korea, is a system using a single carrier method. Therefore, the receiving performance of the digital broadcast receiving system may be deteriorated in a poor channel environment. Particularly, since resistance to changes in channels and noise is more highly required when using portable and/or mobile broadcast receivers, the receiving performance may be even more deteriorated when transmitting mobile service data by the VSB transmission mode.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a digital broadcasting system and a method of processing data that substantially obviate one or more problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a digital broadcasting system and a method of processing data that are highly resistant to channel changes and noise.

Another object of the present invention is to provide a digital broadcast system which additionally encodes electronic program information and transmits the encoded electronic program information to a mobile reception system, thereby improving a reception (Rx) performance of the mobile reception system, and a data processing method for use in the digital broadcast system.

Another object of the present invention is to provide a digital broadcast system which inserts known data recognized by an agreement between a transmission end and a reception end into a predetermined area of a data zone, and transmits electronic program information, thereby improving a reception (Rx) performance of the mobile reception system, and a data processing method for use in the digital broadcast system.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a method for controlling electronic program information comprising: receiving coded mobile service data packet; demodulating the received mobile service data packet; extracting electronic program information from demodulated mobile service data packet; and displaying the extracted electronic program information.

In another aspect of the present invention, there is provided an apparatus for receiving electronic program information comprising: a signal receiving unit for receiving coded mobile service data packet; a demodulating unit for demodulating the received mobile service data packet; a data decoder for extracting electronic program information from the demodulated mobile service data packet; and an application controller for controlling an output of the extracted electronic program information.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 illustrates a block diagram showing a general structure of a digital broadcasting system according to an embodiment of the present invention;

FIG. 2 illustrates a block diagram showing an example of a service multiplexer of FIG. 1;

FIG. 3 illustrates a block diagram showing an example of a transmitter of FIG. 1;

FIG. 4 illustrates a block diagram showing an example of a pre-processor of FIG. 3;

FIG. 5 (a) to FIG. 5( e) illustrate error correction encoding and error detection encoding processed according to an embodiment of the present invention;

FIG. 6A and FIG. 6B illustrate data configuration before and after a data deinterleaver in a digital broadcast transmitting system according to the present invention;

FIG. 7 illustrates a process of dividing a RS frame for configuring a data group according to the present invention;

FIG. 8 illustrates exemplary operations of a packet multiplexer for transmitting the data group according to the present invention;

FIG. 9 illustrates a block diagram showing a structure of a block processor according to the present invention;

FIG. 10 illustrates a detailed block diagram of a symbol encoder shown in FIG. 9;

FIG. 11( a) to FIG. 11( c) illustrate a variable length interleaving process of a symbol interleaver shown in FIG. 9;

FIG. 12A and FIG. 12B illustrate block diagrams showing structures of a block processor according to another embodiment of the present invention;

FIG. 13( a) to FIG. 13( c) illustrate block encoding and trellis encoding processes according to the present invention;

FIG. 14 illustrates a block diagram showing a trellis encoding module according to the present invention;

FIG. 15A and FIG. 15B a block processor and a trellis encoding module connected to one another according to the present invention;

FIG. 16 illustrates a block processor according to another embodiment of the present invention;

FIG. 17 illustrates a block processor according to yet another embodiment of the present invention;

FIG. 18 illustrates an example of a group formatter inserting and transmitting a transmission parameter;

FIG. 19 illustrates an example of a block processor inserting and transmitting a transmission parameter;

FIG. 20 illustrates an example of a packet formatter inserting and transmitting a transmission parameter;

FIG. 21 illustrates an example for inserting and transmitting the transmission parameter in a field synchronization segment area;

FIG. 22 illustrates a block diagram showing a structure of a digital broadcast receiving system according to the present invention;

FIG. 23 is a block diagram illustrating a reception system according to the present invention;

FIG. 24 is a conceptual diagram illustrating an exemplary error correction decoding process according to the present invention;

FIG. 25 is a structural diagram illustrating a bit stream syntax associated with an Event Information Table (EIT) including electronic program information according to the present invention;

FIG. 26A is a structural diagram illustrating a syntax structure associated with a table indicating current time information according to the present invention;

FIG. 26B is a structural diagram illustrating a local time offset descriptor syntax according to the present invention;

FIG. 27 is a structural diagram illustrating a syntax associated with a local time offset table according to the present invention;

FIG. 28 shows a display format of an Electronic Program Guide (EPG) according to the present invention;

FIG. 29 shows an output format of an Electronic Program Guide (EPG) according to an embodiment of the present invention;

FIG. 30 shows an output format of an Electronic Program Guide (EPG) according to another embodiment of the present invention;

FIG. 31 shows another output format of an Electronic Program Guide (EPG) according to another embodiment of the present invention;

FIG. 32 shows another output format of an Electronic Program Guide (EPG) according to another embodiment of the present invention;

FIG. 33 shows another output format of an Electronic Program Guide (EPG) according to another embodiment of the present invention;

FIGS. 34A and 34B show two-dimensional pivot functions according to an embodiment of the present invention;

FIG. 35 is a flow chart illustrating an EPG implementation method according to the present invention;

FIG. 36A to FIG. 36C show EPG implementation examples according to an embodiment of the present invention;

FIG. 37 is a flow chart illustrating a method for implementing an EPG preview function of FIG. 36A to FIG. 36C according to an embodiment of the present invention;

FIG. 38 is a flow chart illustrating a method for implementing an EPG preview function of FIG. 36A to FIG. 36C according to another embodiment of the present invention;

FIG. 39A to FIG. 39C show EPG implementation examples according to another embodiment of the present invention;

FIG. 40 is a flow chart illustrating a method for implementing details information of a program list according to the present invention;

FIG. 41 is a conceptual diagram illustrating an EPG implementation according to another embodiment of the present invention;

FIG. 42A and FIG. 42B show output views of integrated source program information according to the present invention;

FIG. 43 is a conceptual diagram illustrating an EPG implementation according to another embodiment of the present invention;

FIG. 44A to FIG. 44B show output views of details information of other information according to the present invention;

FIG. 46 is a conceptual diagram illustrating an EPG implementation according to another embodiment of the present invention;

FIG. 47 is a conceptual diagram illustrating an EPG implementation according to another embodiment of the present invention;

FIG. 48A and FIG. 48B are conceptual diagrams illustrating a process for establishing a Rating Region Table (RRT) function according to the present invention;

FIG. 49 is a conceptual diagram illustrating an EPG implementation associated with update of program information according to an embodiment of the present invention; and

FIG. 50 is a conceptual diagram illustrating an EPG implementation associated with update of program information according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In addition, although the terms used in the present invention are selected from generally known and used terms, some of the terms mentioned in the description of the present invention have been selected by the applicant at his or her discretion, the detailed meanings of which are described in relevant parts of the description herein. Furthermore, it is required that the present invention is understood, not simply by the actual terms used but by the meaning of each term lying within.

Among the terms used in the description of the present invention, main service data correspond to data that can be received by a fixed receiving system and may include audio/video (A/V) data. More specifically, the main service data may include A/V data of high definition (HD) or standard definition (SD) levels and may also include diverse data types required for data broadcasting. Also, the known data correspond to data pre-known in accordance with a pre-arranged agreement between the receiving system and the transmitting system. Additionally, in the present invention, mobile service data may include at least one of mobile service data, pedestrian service data, and handheld service data, and are collectively referred to as mobile service data for simplicity. Herein, the mobile service data not only correspond to mobile/pedestrian/handheld service data (M/P/H service data) but may also include any type of service data with mobile or portable characteristics. Therefore, the mobile service data according to the present invention are not limited only to the M/P/H service data.

The above-described mobile service data may correspond to data having information, such as program execution files, stock information, and so on, and may also correspond to A/V data. Most particularly, the mobile service data may correspond to A/V data having lower resolution and lower data rate as compared to the main service data. For example, if an A/V codec that is used for a conventional main service corresponds to a MPEG-2 codec, a MPEG-4 advanced video coding (AVC) or scalable video coding (SVC) having better image compression efficiency may be used as the A/V codec for the mobile service. Furthermore, any type of data may be transmitted as the mobile service data. For example, transport protocol expert group (TPEG) data for broadcasting real-time transportation information may be serviced as the main service data.

Also, a data service using the mobile service data may include weather forecast services, traffic information services, stock information services, viewer participation quiz programs, real-time polls & surveys, interactive education broadcast programs, gaming services, services providing information on synopsis, character, background music, and filming sites of soap operas or series, services providing information on past match scores and player profiles and achievements, and services providing information on product information and programs classified by service, medium, time, and theme enabling purchase orders to be processed. Herein, the present invention is not limited only to the services mentioned above.

Electronic program information is information of the mobile service data. In this case, the electronic program information may be program information associated with a channel and time of A/V data contained in the mobile service data, or may also be channel- and time-information associated with either data broadcasting or software updating. However, it should be noted that the above-mentioned examples are disclosed for only illustrative purposes. Needless to say, the above-mentioned electronic program information of the present invention includes all information including the above-mentioned mobile service data description.

The electronic program information contained in the PSI/PSIP data is transmitted to a destination. If there is a specific table equipped with program information in the PSIP/PSI table, a transmitter may include electronic program information in all kinds of tables, and transmit the resultant table including the electronic program information.

A receiver may extract program information from all kinds of tables, and provide a user with the program information. In an embodiment of the present invention, the receiver extracts the program information from an Event Information Table (EIT) or a Virtual Channel Table (VCT), and provide the user with the extracted program information.

If an unexpected error occurs while the transmitter transmits electronic program information to the receiver, the receiver may not transmit the program information to the user, or may transmit wrong information to the user. Therefore, there is needed a system capable of transmitting the electronic program information from the transmitter to the receiver under a mobile reception environment.

A transmission system according to the present invention has no influence on a conventional reception system while the conventional reception system receives main service data. Namely, the transmission system is backward compatible with the reception system. And, the transmission system multiplexes main service data and mobile service data in the same physical channel, and transmits the multiplexed data.

The transmission system according to the present invention additionally encodes mobile service data and electronic program information, inserts known data pre-recognized by an agreement between the transmission/reception ends into the encoded result, and transmits the inserted result.

In the case of using the above-mentioned transmission system, the reception system can receive mobile service data while in motion, and can stably receive the mobile service data irrespective of a distortion or noise of a channel.

General Description of a Transmitting System

FIG. 1 illustrates a block diagram showing a general structure of a digital broadcast transmitting system according to an embodiment of the present invention. Herein, the digital broadcast transmitting includes a service multiplexer 100 and a transmitter 200. Herein, the service multiplexer 100 is located in the studio of each broadcast station, and the transmitter 200 is located in a site placed at a predetermined distance from the studio. The transmitter 200 may be located in a plurality of different locations. Also, for example, the plurality of transmitters may share the same frequency. And, in this case, the plurality of transmitters receives the same signal. Accordingly, in the receiving system, a channel equalizer may compensate signal distortion, which is caused by a reflected wave, so as to recover the original signal. In another example, the plurality of transmitters may have different frequencies with respect to the same channel.

A variety of methods may be used for data communication each of the transmitters, which are located in remote positions, and the service multiplexer. For example, an interface standard such as a synchronous serial interface for transport of MPEG-2 data (SMPTE-310M). In the SMPTE-310M interface standard, a constant data rate is decided as an output data rate of the service multiplexer. For example, in case of the 8VSB mode, the output data rate is 19.39 Mbps, and, in case of the 16VSB mode, the output data rate is 38.78 Mbps. Furthermore, in the conventional 8VSB mode transmitting system, a transport stream (TS) packet having a data rate of approximately 19.39 Mbps may be transmitted through a single physical channel. Also, in the transmitting system according to the present invention provided with backward compatibility with the conventional transmitting system, additional encoding is performed on the mobile service data. Thereafter, the additionally encoded mobile service data are multiplexed with the main service data to a TS packet form, which is then transmitted. At this point, the data rate of the multiplexed TS packet is approximately 19.39 Mbps.

At this point, the service multiplexer 100 receives at least one type of mobile service data and program specific information (PSI)/program and system information protocol (PSIP) table data for each mobile service and encapsulates the received data to each transport stream (TS) packet. Also, the service multiplexer 100 receives at least one type of main service data and PSI/PSIP table data for each main service so as to encapsulate the received data to a TS packet. Subsequently, the TS packets are multiplexed according to a predetermined multiplexing rule and outputs the multiplexed packets to the transmitter 200.

Service Multiplexer

FIG. 2 illustrates a block diagram showing an example of the service multiplexer. The service multiplexer includes a controller 110 for controlling the overall operations of the service multiplexer, a PSI/PSIP generator 120 for the main service, a PSI/PSIP generator 130 for the mobile service, a null packet generator 140, a mobile service multiplexer 150, and a transport multiplexer 160. The transport multiplexer 160 may include a main service multiplexer 161 and a transport stream (TS) packet multiplexer 162. Referring to FIG. 2, at least one type of compression encoded main service data and the PSI/PSIP table data generated from the PSI/PSIP generator 120 for the main service are inputted to the main service multiplexer 161 of the transport multiplexer 160. The main service multiplexer 161 encapsulates each of the inputted main service data and PSI/PSIP table data to MPEG-2 TS packet forms. Then, the MPEG-2 TS packets are multiplexed and outputted to the TS packet multiplexer 162. Herein, the data packet being outputted from the main service multiplexer 161 will be referred to as a main service data packet for simplicity.

Thereafter, at least one type of the compression encoded mobile service data and the PSI/PSIP table data generated from the PSI/PSIP generator 130 for the mobile service are inputted to the mobile service multiplexer 150. The mobile service multiplexer 150 encapsulates each of the inputted mobile service data and PSI/PSIP table data to MPEG-2 TS packet forms. Then, the MPEG-2 TS packets are multiplexed and outputted to the TS packet multiplexer 162. Herein, the data packet being outputted from the mobile service multiplexer 150 will be referred to as a mobile service data packet for simplicity. At this point, the transmitter 200 requires identification information in order to identify and process the main service data packet and the mobile service data packet. Herein, the identification information may use values pre-decided in accordance with an agreement between the transmitting system and the receiving system, or may be configured of a separate set of data, or may modify predetermined location value with in the corresponding data packet. As an example of the present invention, a different packet identifier (PID) may be assigned to identify each of the main service data packet and the mobile service data packet.

In another example, by modifying a synchronization data byte within a header of the mobile service data, the service data packet may be identified by using the synchronization data byte value of the corresponding service data packet. For example, the synchronization byte of the main service data packet directly outputs the value decided by the ISO/IEC13818-1 standard (i.e., 0x47) without any modification. The synchronization byte of the mobile service data packet modifies and outputs the value, thereby identifying the main service data packet and the mobile service data packet. Conversely, the synchronization byte of the main service data packet is modified and outputted, whereas the synchronization byte of the mobile service data packet is directly outputted without being modified, thereby enabling the main service data packet and the mobile service data packet to be identified.

A plurality of methods may be applied in the method of modifying the synchronization byte. For example, each bit of the synchronization byte may be inversed, or only a portion of the synchronization byte may be inversed. As described above, any type of identification information may be used to identify the main service data packet and the mobile service data packet. Therefore, the scope of the present invention is not limited only to the example set forth in the description of the present invention.

Meanwhile, a transport multiplexer used in the conventional digital broadcasting system may be used as the transport multiplexer 160 according to the present invention. More specifically, in order to multiplex the mobile service data and the main service data and to transmit the multiplexed data, the data rate of the main service is limited to a data rate of (19.39-K) Mbps. Then, K Mbps, which corresponds to the remaining data rate, is assigned as the data rate of the mobile service. Thus, the transport multiplexer which is already being used may be used as it is without any modification. Herein, the transport multiplexer 160 multiplexes the main service data packet being outputted from the main service multiplexer 161 and the mobile service data packet being outputted from the mobile service multiplexer 150. Thereafter, the transport multiplexer 160 transmits the multiplexed data packets to the transmitter 200.

However, in some cases, the output data rate of the mobile service multiplexer 150 may not be equal to K Mbps. In this case, the mobile service multiplexer 150 multiplexes and outputs null data packets generated from the null packet generator 140 so that the output data rate can reach K Mbps. More specifically, in order to match the output data rate of the mobile service multiplexer 150 to a constant data rate, the null packet generator 140 generates null data packets, which are then outputted to the mobile service multiplexer 150. For example, when the service multiplexer 100 assigns K Mbps of the 19.39 Mbps to the mobile service data, and when the remaining (19.39-K) Mbps is, therefore, assigned to the main service data, the data rate of the mobile service data that are multiplexed by the service multiplexer 100 actually becomes lower than K Mbps. This is because, in case of the mobile service data, the pre-processor of the transmitting system performs additional encoding, thereby increasing the amount of data. Eventually, the data rate of the mobile service data, which may be transmitted from the service multiplexer 100, becomes smaller than K Mbps.

For example, since the pre-processor of the transmitter performs an encoding process on the mobile service data at a coding rate of at least ½, the amount of the data outputted from the pre-processor is increased to more than twice the amount of the data initially inputted to the pre-processor. Therefore, the sum of the data rate of the main service data and the data rate of the mobile service data, both being multiplexed by the service multiplexer 100, becomes either equal to or smaller than 19.39 Mbps. Therefore, in order to match the data rate of the data that are finally outputted from the service multiplexer 100 to a constant data rate (e.g., 19.39 Mbps), an amount of null data packets corresponding to the amount of lacking data rate is generated from the null packet generator 140 and outputted to the mobile service multiplexer 150.

Accordingly, the mobile service multiplexer 150 encapsulates each of the mobile service data and the PSI/PSIP table data that are being inputted to a MPEG-2 TS packet form. Then, the above-described TS packets are multiplexed with the null data packets and, then, outputted to the TS packet multiplexer 162. Thereafter, the TS packet multiplexer 162 multiplexes the main service data packet being outputted from the main service multiplexer 161 and the mobile service data packet being outputted from the mobile service multiplexer 150 and transmits the multiplexed data packets to the transmitter 200 at a data rate of 19.39 Mbps.

According to an embodiment of the present invention, the mobile service multiplexer 150 receives the null data packets. However, this is merely exemplary and does not limit the scope of the present invention. In other words, according to another embodiment of the present invention, the TS packet multiplexer 162 may receive the null data packets, so as to match the data rate of the finally outputted data to a constant data rate. Herein, the output path and multiplexing rule of the null data packet is controlled by the controller 110. The controller 110 controls the multiplexing processed performed by the mobile service multiplexer 150, the main service multiplexer 161 of the transport multiplexer 160, and the TS packet multiplexer 162, and also controls the null data packet generation of the null packet generator 140. At this point, the transmitter 200 discards the null data packets transmitted from the service multiplexer 100 instead of transmitting the null data packets.

Further, in order to allow the transmitter 200 to discard the null data packets transmitted from the service multiplexer 100 instead of transmitting them, identification information for identifying the null data packet is required. Herein, the identification information may use values pre-decided in accordance with an agreement between the transmitting system and the receiving system. For example, the value of the synchronization byte within the header of the null data packet may be modified so as to be used as the identification information. Alternatively, a transport_error _indicator flag may also be used as the identification information.

In the description of the present invention, an example of using the transport_error_indicator flag as the identification information will be given to describe an embodiment of the present invention. In this case, the transport_error_indicator flag of the null data packet is set to ‘1’, and the transport_error_indicator flag of the remaining data packets are reset to ‘0’, so as to identify the null data packet. More specifically, when the null packet generator 140 generates the null data packets, if the transport_error_indicator flag from the header field of the null data packet is set to ‘1’ and then transmitted, the null data packet may be identified and, therefore, be discarded. In the present invention, any type of identification information for identifying the null data packets may be used. Therefore, the scope of the present invention is not limited only to the examples set forth in the description of the present invention.

According to another embodiment of the present invention, a transmission parameter may be included in at least a portion of the null data packet, or at least one table or an operations and maintenance (OM) packet (or OMP) of the PSI/PSIP table for the mobile service. In this case, the transmitter 200 extracts the transmission parameter and outputs the extracted transmission parameter to the corresponding block and also transmits the extracted parameter to the receiving system if required. More specifically, a packet referred to as an OMP is defined for the purpose of operating and managing the transmitting system. For example, the OMP is configured in accordance with the MPEG-2 TS packet format, and the corresponding PID is given the value of 0x1FFA. The OMP is configured of a 4-byte header and a 184-byte payload. Herein, among the 184 bytes, the first byte corresponds to an OM_type field, which indicates the type of the OM packet.

In the present invention, the transmission parameter may be transmitted in the form of an OMP. And, in this case, among the values of the reserved fields within the OM_type field, a pre-arranged value is used, thereby indicating that the transmission parameter is being transmitted to the transmitter 200 in the form of an OMP. More specifically, the transmitter 200 may find (or identify) the OMP by referring to the PID. Also, by parsing the OM_type field within the OMP, the transmitter 200 can verify whether a transmission parameter is included after the OM_type field of the corresponding packet. The transmission parameter corresponds to supplemental data required for processing mobile service data from the transmitting system and the receiving system.

Herein, the transmission parameter may include data group information, region information within the data group, RS frame information, super frame information, burst information, turbo code information, and RS code information. The burst information may include burst size information, burst period information, and time information to next burst. The burst period signifies the period at which the burst transmitting the same mobile service is repeated. The data group includes a plurality of mobile service data packets, and a plurality of such data groups is gathered (or grouped) to form a burst. A burst section signifies the beginning of a current burst to the beginning of a next burst. Herein, the burst section is classified as a section that includes the data group (also referred to as a burst-on section), and a section that does not include the data group (also referred to as a burst-off section). A burst-on section is configured of a plurality of fields, wherein one field includes one data group.

The transmission parameter may also include information on how signals of a symbol domain are encoded in order to transmit the mobile service data, and multiplexing information on how the main service data and the mobile service data or various types of mobile service data are multiplexed. The information included in the transmission parameter is merely exemplary to facilitate the understanding of the present invention. And, the adding and deleting of the information included in the transmission parameter may be easily modified and changed by anyone skilled in the art. Therefore, the present invention is not limited to the examples proposed in the description set forth herein. Furthermore, the transmission parameters may be provided from the service multiplexer 100 to the transmitter 200. Alternatively, the transmission parameters may also be set up by an internal controller (not shown) within the transmitter 200 or received from an external source.

Transmitter

FIG. 3 illustrates a block diagram showing an example of the transmitter 200 according to an embodiment of the present invention. Herein, the transmitter 200 includes a demultiplexer 210, a packet jitter mitigator 220, a pre-processor 230, a packet multiplexer 240, a post-processor 250, a synchronization (sync) multiplexer 260, and a transmission unit 270. Herein, when a data packet is received from the service multiplexer 100, the demultiplexer 210 should identify whether the received data packet corresponds to a main service data packet, a mobile service data packet, or a null data packet. For example, the demultiplexer 210 uses the PID within the received data packet so as to identify the main service data packet and the mobile service data packet. Then, the demultiplexer 210 uses a transport_error_indicator field to identify the null data packet. The main service data packet identified by the demultiplexer 210 is outputted to the packet jitter mitigator 220, the mobile service data packet is outputted to the pre-processor 230, and the null data packet is discarded. If a transmission parameter is included in the null data packet, then the transmission parameter is first extracted and outputted to the corresponding block. Thereafter, the null data packet is discarded.

The pre-processor 230 performs an additional encoding process of the mobile service data included in the service data packet, which is demultiplexed and outputted from the demultiplexer 210. The pre-processor 230 also performs a process of configuring a data group so that the data group may be positioned at a specific place in accordance with the purpose of the data, which are to be transmitted on a transmission frame. This is to enable the mobile service data to respond swiftly and strongly against noise and channel changes. The pre-processor 230 may also refer to the transmission parameter when performing the additional encoding process. Also, the pre-processor 230 groups a plurality of mobile service data packets to configure a data group. Thereafter, known data, mobile service data, RS parity data, and MPEG header are allocated to pre-determined areas within the data group.

Pre-Processor within Transmitter

FIG. 4 illustrates a block diagram showing an example of the pre-processor 230 according to the present invention. The pre-processor 230 includes a data randomizer 301, a RS frame encoder 302, a block processor 303, a group formatter 304, a data deinterleaver 305, a packet formatter 306. The data randomizer 301 within the above-described pre-processor 230 randomizes the mobile service data packet including the mobile service data that is inputted through the demultiplexer 210. Then, the data randomizer 301 outputs the randomized mobile service data packet to the RS frame encoder 302. At this point, since the data randomizer 301 performs the randomizing process on the mobile service data, the randomizing process that is to be performed by the data randomizer 251 of the post-processor 250 on the mobile service data may be omitted. The data randomizer 301 may also discard the synchronization byte within the mobile service data packet and perform the randomizing process. This is an option that may be chosen by the system designer. In the example given in the present invention, the randomizing process is performed without discarding the synchronization byte within the mobile service data packet.

The RS frame encoder 302 groups a plurality of mobile the synchronization byte within the mobile service data packets that is randomized and inputted, so as to create a RS frame. Then, the RS frame encoder 302 performs at least one of an error correction encoding process and an error detection encoding process in RS frame units. Accordingly, robustness may be provided to the mobile service data, thereby scattering group error that may occur during changes in a frequency environment, thereby enabling the enhanced data to respond to the frequency environment, which is extremely vulnerable and liable to frequent changes. Also, the RS frame encoder 302 groups a plurality of RS frame so as to create a super frame, thereby performing a row permutation process in super frame units. The row permutation process may also be referred to as a row interleaving process. Hereinafter, the process will be referred to as row permutation for simplicity.

More specifically, when the RS frame encoder 302 performs the process of permuting each row of the super frame in accordance with a pre-determined rule, the position of the rows within the super frame before and after the row permutation process is changed. If the row permutation process is performed by super frame units, and even though the section having a plurality of errors occurring therein becomes very long, and even though the number of errors included in the RS frame, which is to be decoded, exceeds the extent of being able to be corrected, the errors become dispersed within the entire super frame. Thus, the decoding ability is even more enhanced as compared to a single RS frame.

At this point, as an example of the present invention, RS-encoding is applied for the error correction encoding process, and a cyclic redundancy check (CRC) encoding is applied for the error detection process. When performing the RS-encoding, parity data that are used for the error correction are generated. And, when performing the CRC encoding, CRC data that are used for the error detection are generated. The RS encoding is one of forward error correction (FEC) methods. The FEC corresponds to a technique for compensating errors that occur during the transmission process. The CRC data generated by CRC encoding may be used for indicating whether or not the mobile service data have been damaged by the errors while being transmitted through the channel. In the present invention, a variety of error detection coding methods other than the CRC encoding method may be used, or the error correction coding method may be used to enhance the overall error correction ability of the receiving system. Herein, the RS frame encoder 302 refers to a pre-determined transmission parameter and/or the transmission parameter provided from the service multiplexer 100 so as to perform operations including RS frame configuration, RS encoding, CRC encoding, super frame configuration, and row permutation in super frame units.

Pre-Processor within RS Frame Encoder

FIG. 5( a) to FIG. 5( e) illustrate error correction encoding and error detection encoding processed according to an embodiment of the present invention. More specifically, the RS frame encoder 302 first divides the inputted mobile service data bytes to units of a predetermined length. The predetermined length is decided by the system designer. And, in the example of the present invention, the predetermined length is equal to 187 bytes, and, therefore, the 187-byte unit will be referred to as a packet for simplicity. For example, when the mobile service data that are being inputted, as shown in FIG. 5( a), correspond to a MPEG transport packet stream configured of 188-byte units, the first synchronization byte is removed, as shown in FIG. 5( b), so as to configure a 187-byte unit. Herein, the synchronization byte is removed because each mobile service data packet has the same value.

Herein, the process of removing the synchronization byte may be performed during a randomizing process of the data randomizer 301 in an earlier process. In this case, the process of the removing the synchronization byte by the RS frame encoder 302 may be omitted. Moreover, when adding synchronization bytes from the receiving system, the process may be performed by the data derandomizer instead of the RS frame decoder. Therefore, if a removable fixed byte (e.g., synchronization byte) does not exist within the mobile service data packet that is being inputted to the RS frame encoder 302, or if the mobile service data that are being inputted are not configured in a packet format, the mobile service data that are being inputted are divided into 187-byte units, thereby configuring a packet for each 187-byte unit.

Subsequently, as shown in FIG. 5( c), N number of packets configured of 187 bytes is grouped to configure a RS frame. At this point, the RS frame is configured as a RS frame having the size of N(row)*187(column) bytes, in which 187-byte packets are sequentially inputted in a row direction. In order to simplify the description of the present invention, the RS frame configured as described above will also be referred to as a first RS frame. More specifically, only pure mobile service data are included in the first RS frame, which is the same as the structure configured of 187 N-byte rows. Thereafter, the mobile service data within the RS frame are divided into an equal size. Then, when the divided mobile service data are transmitted in the same order as the input order for configuring the RS frame, and when one or more errors have occurred at a particular point during the transmitting/receiving process, the errors are clustered (or gathered) within the RS frame as well. In this case, the receiving system uses a RS erasure decoding method when performing error correction decoding, thereby enhancing the error correction ability. At this point, the N number of columns within the N number of RS frame includes 187 bytes, as shown in FIG. 5( c).

In this case, a (Nc,Kc)-RS encoding process is performed on each column, so as to generate Nc−Kc(=P) number of parity bytes. Then, the newly generated P number of parity bytes is added after the very last byte of the corresponding column, thereby creating a column of (187+P) bytes. Herein, as shown in FIG. 5( c), Kc is equal to 187 (i.e., Kc=187), and Nc is equal to 187+P (i.e., Nc=187+P). For example, when P is equal to 48, (235,187)-RS encoding process is performed so as to create a column of 235 bytes. When such RS encoding process is performed on all N number of columns, as shown in FIG. 5( c), a RS frame having the size of N(row)*(187+P)(column) bytes may be created, as shown in FIG. 5( d). In order to simplify the description of the present invention, the RS frame having the RS parity inserted therein will be referred to as s second RS frame. More specifically, the second RS frame having the structure of (187+P) rows configured of N bytes may be configured.

As shown in FIG. 5( c) or FIG. 5( d), each row of the RS frame is configured of N bytes. However, depending upon channel conditions between the transmitting system and the receiving system, error may be included in the RS frame. When errors occur as described above, CRC data (or CRC code or CRC checksum) may be used on each row unit in order to verify whether error exists in each row unit. The RS frame encoder 302 may perform CRC encoding on the mobile service data being RS encoded so as to create (or generate) the CRC data. The CRC data being generated by CRC encoding may be used to indicate whether the mobile service data have been damaged while being transmitted through the channel.

The present invention may also use different error detection encoding methods other than the CRC encoding method. Alternatively, the present invention may use the error correction encoding method to enhance the overall error correction ability of the receiving system. FIG. 5( e) illustrates an example of using a 2-byte (i.e., 16-bit) CRC checksum as the CRC data. Herein, a 2-byte CRC checksum is generated for N number of bytes of each row, thereby adding the 2-byte CRC checksum at the end of the N number of bytes. Thus, each row is expanded to (N+2) number of bytes. Equation 1 below corresponds to an exemplary equation for generating a 2-byte CRC checksum for each row being configured of N number of bytes. g(x)=x ¹⁶ +x ¹² +x ⁵+1  Equation 1

The process of adding a 2-byte checksum in each row is only exemplary. Therefore, the present invention is not limited only to the example proposed in the description set forth herein. In order to simplify the understanding of the present invention, the RS frame having the RS parity and CRC checksum added therein will hereinafter be referred to as a third RS frame. More specifically, the third RS frame corresponds to (187+P) number of rows each configured of (N+2) number of bytes. As described above, when the process of RS encoding and CRC encoding are completed, the (N*187)-byte RS frame is expanded to a (N+2)*(187+P)-byte RS frame. Furthermore, the RS frame that is expanded, as shown in FIG. 5( e), is inputted to the block processor 303.

As described above, the mobile service data encoded by the RS frame encoder 302 are inputted to the block processor 303. The block processor 303 then encodes the inputted mobile service data at a coding rate of G/H (wherein, G is smaller than H (i.e., G<H)) and then outputted to the group formatter 304. More specifically, the block processor 303 divides the mobile service data being inputted in byte units into bit units. Then, the G number of bits is encoded to H number of bits. Thereafter, the encoded bits are converted back to byte units and then outputted. For example, if 1 bit of the input data is coded to 2 bits and outputted, then G is equal to 1 and H is equal to 2 (i.e., G=1 and H=2). Alternatively, if 1 bit of the input data is coded to 4 bits and outputted, then G is equal to 1 and H is equal to 4 (i.e., G=1 and H=4). Hereinafter, the former coding rate will be referred to as a coding rate of ½ (½-rate coding), and the latter coding rate will be referred to as a coding rate of ¼ (¼-rate coding), for simplicity.

Herein, when using the ¼ coding rate, the coding efficiency is greater than when using the ½ coding rate, and may, therefore, provide greater and enhanced error correction ability. For such reason, when it is assumed that the data encoded at a ¼ coding rate in the group formatter 304, which is located near the end portion of the system, are allocated to an area in which the receiving performance may be deteriorated, and that the data encoded at a ½ coding rate are allocated to an area having excellent receiving performance, the difference in performance may be reduced. At this point, the block processor 303 may also receive signaling information including transmission parameters. Herein, the signaling information may also be processed with either ½-rate coding or ¼-rate coding as in the step of processing mobile service data. Thereafter, the signaling information is also considered the same as the mobile service data and processed accordingly.

Meanwhile, the group formatter inserts mobile service data that are outputted from the block processor 303 in corresponding areas within a data group, which is configured in accordance with a pre-defined rule. Also, with respect to the data deinterleaving process, each place holder or known data (or known data place holders) are also inserted in corresponding areas within the data group. At this point, the data group may be divided into at least one hierarchical area. Herein, the type of mobile service data being inserted in each area may vary depending upon the characteristics of each hierarchical area. Additionally, each area may, for example, be divided based upon the receiving performance within the data group. Furthermore, one data group may be configured to include a set of field synchronization data.

In an example given in the present invention, a data group is divided into A, B, and C regions in a data configuration prior to data deinterleaving. At this point, the group formatter 304 allocates the mobile service data, which are inputted after being RS encoded and block encoded, to each of the corresponding regions by referring to the transmission parameter. FIG. 6A illustrates an alignment of data after being data interleaved and identified, and FIG. 6B illustrates an alignment of data before being data interleaved and identified. More specifically, a data structure identical to that shown in FIG. 6A is transmitted to a receiving system. Also, the data group configured to have the same structure as the data structure shown in FIG. 6A is inputted to the data deinterleaver 305.

As described above, FIG. 6A illustrates a data structure prior to data deinterleaving that is divided into 3 regions, such as region A, region B, and region C. Also, in the present invention, each of the regions A to C is further divided into a plurality of regions. Referring to FIG. 6A, region A is divided into 5 regions (A1 to A5), region B is divided into 2 regions (B1 and B2), and region C is divided into 3 regions (C1 to C3). Herein, regions A to C are identified as regions having similar receiving performances within the data group. Herein, the type of mobile service data, which are inputted, may also vary depending upon the characteristic of each region.

In the example of the present invention, the data structure is divided into regions A to C based upon the level of interference of the main service data. Herein, the data group is divided into a plurality of regions to be used for different purposes. More specifically, a region of the main service data having no interference or a very low interference level may be considered to have a more resistant (or stronger) receiving performance as compared to regions having higher interference levels. Additionally, when using a system inserting and transmitting known data in the data group, and when consecutively long known data are to be periodically inserted in the mobile service data, the known data having a predetermined length may be periodically inserted in the region having no interference from the main service data (e.g., region A). However, due to interference from the main service data, it is difficult to periodically insert known data and also to insert consecutively long known data to a region having interference from the main service data (e.g., region B and region C).

Hereinafter, examples of allocating data to region A (A1 to A5), region B (B1 and B2), and region C (C1 to C3) will now be described in detail with reference to FIG. 6A. The data group size, the number of hierarchically divided regions within the data group and the size of each region, and the number of mobile service data bytes that can be inserted in each hierarchically divided region of FIG. 6A are merely examples given to facilitate the understanding of the present invention. Herein, the group formatter 304 creates a data group including places in which field synchronization data bytes are to be inserted, so as to create the data group that will hereinafter be described in detail.

More specifically, region A is a region within the data group in which a long known data sequence may be periodically inserted, and in which includes regions wherein the main service data are not mixed (e.g., A1 to A5). Also, region A includes a region (e.g., A1) located between a field synchronization region and the region in which the first known data sequence is to be inserted. The field synchronization region has the length of one segment (i.e., 832 symbols) existing in an ATSC system.

For example, referring to FIG. 6A, 2428 bytes of the mobile service data may be inserted in region A1, 2580 bytes may be inserted in region A2, 2772 bytes may be inserted in region A3, 2472 bytes may be inserted in region A4, and 2772 bytes may be inserted in region A5. Herein, trellis initialization data or known data, MPEG header, and RS parity are not included in the mobile service data. As described above, when region A includes a known data sequence at both ends, the receiving system uses channel information that can obtain known data or field synchronization data, so as to perform equalization, thereby providing enforced equalization performance.

Also, region B includes a region located within 8 segments at the beginning of a field synchronization region within the data group (chronologically placed before region A1) (e.g., region B1), and a region located within 8 segments behind the very last known data sequence which is inserted in the data group (e.g., region B2). For example, 930 bytes of the mobile service data may be inserted in the region B1, and 1350 bytes may be inserted in region B2. Similarly, trellis initialization data or known data, MPEG header, and RS parity are not included in the mobile service data. In case of region B, the receiving system may perform equalization by using channel information obtained from the field synchronization region. Alternatively, the receiving system may also perform equalization by using channel information that may be obtained from the last known data sequence, thereby enabling the system to respond to the channel changes.

Region C includes a region located within 30 segments including and preceding the 9^(th) segment of the field synchronization region (chronologically located before region A) (e.g., region C1), a region located within 12 segments including and following the 9^(th) segment of the very last known data sequence within the data group (chronologically located after region A) (e.g., region C2), and a region located in 32 segments after the region C2 (e.g., region C3). For example, 1272 bytes of the mobile service data may be inserted in the region C1, 1560 bytes may be inserted in region C2, and 1312 bytes may be inserted in region C3. Similarly, trellis initialization data or known data, MPEG header, and RS parity are not included in the mobile service data. Herein, region C (e.g., region C1) is located chronologically earlier than (or before) region A.

Since region C (e.g., region C1) is located further apart from the field synchronization region which corresponds to the closest known data region, the receiving system may use the channel information obtained from the field synchronization data when performing channel equalization. Alternatively, the receiving system may also use the most recent channel information of a previous data group. Furthermore, in region C (e.g., region C2 and region C3) located before region A, the receiving system may use the channel information obtained from the last known data sequence to perform equalization. However, when the channels are subject to fast and frequent changes, the equalization may not be performed perfectly. Therefore, the equalization performance of region C may be deteriorated as compared to that of region B.

When it is assumed that the data group is allocated with a plurality of hierarchically divided regions, as described above, the block processor 303 may encode the mobile service data, which are to be inserted to each region based upon the characteristic of each hierarchical region, at a different coding rate. For example, the block processor 303 may encode the mobile service data, which are to be inserted in regions A1 to A5 of region A, at a coding rate of ½. Then, the group formatter 304 may insert the ½-rate encoded mobile service data to regions A1 to A5.

The block processor 303 may encode the mobile service data, which are to be inserted in regions B1 and B2 of region B, at a coding rate of ¼ having higher error correction ability as compared to the ½-coding rate. Then, the group formatter 304 inserts the ¼-rate coded mobile service data in region B1 and region B2. Furthermore, the block processor 303 may encode the mobile service data, which are to be inserted in regions C1 to C3 of region C, at a coding rate of ¼ or a coding rate having higher error correction ability than the ¼-coding rate. Then, the group formatter 304 may either insert the encoded mobile service data to regions C1 to C3, as described above, or leave the data in a reserved region for future usage.

In addition, the group formatter 304 also inserts supplemental data, such as signaling information that notifies the overall transmission information, other than the mobile service data in the data group. Also, apart from the encoded mobile service data outputted from the block processor 303, the group formatter 304 also inserts MPEG header place holders, non-systematic RS parity place holders, main service data place holders, which are related to data deinterleaving in a later process, as shown in FIG. 6A. Herein, the main service data place holders are inserted because the mobile service data bytes and the main service data bytes are alternately mixed with one another in regions B and C based upon the input of the data deinterleaver, as shown in FIG. 6A. For example, based upon the data outputted after data deinterleaving, the place holder for the MPEG header may be allocated at the very beginning of each packet.

Furthermore, the group formatter 304 either inserts known data generated in accordance with a pre-determined method or inserts known data place holders for inserting the known data in a later process. Additionally, place holders for initializing the trellis encoding module 256 are also inserted in the corresponding regions. For example, the initialization data place holders may be inserted in the beginning of the known data sequence. Herein, the size of the mobile service data that can be inserted in a data group may vary in accordance with the sizes of the trellis initialization place holders or known data (or known data place holders), MPEG header place holders, and RS parity place holders.

The output of the group formatter 304 is inputted to the data deinterleaver 305. And, the data deinterleaver 305 deinterleaves data by performing an inverse process of the data interleaver on the data and place holders within the data group, which are then outputted to the packet formatter 306. More specifically, when the data and place holders within the data group configured, as shown in FIG. 6A, are deinterleaved by the data deinterleaver 305, the data group being outputted to the packet formatter 306 is configured to have the structure shown in FIG. 6B.

The packet formatter 306 removes the main service data place holders and the RS parity place holders that were allocated for the deinterleaving process from the deinterleaved data being inputted. Then, the packet formatter 306 groups the remaining portion and replaces the 4-byte MPEG header place holder with an MPEG header having a null packet PID (or an unused PID from the main service data packet). Also, when the group formatter 304 inserts known data place holders, the packet formatter 306 may insert actual known data in the known data place holders, or may directly output the known data place holders without any modification in order to make replacement insertion in a later process. Thereafter, the packet formatter 306 identifies the data within the packet-formatted data group, as described above, as a 188-byte unit mobile service data packet (i.e., MPEG TS packet), which is then provided to the packet multiplexer 240.

The packet multiplexer 240 multiplexes the mobile service data packet outputted from the pre-processor 230 and the main service data packet outputted from the packet jitter mitigator 220 in accordance with a pre-defined multiplexing method. Then, the packet multiplexer 240 outputs the multiplexed data packets to the data randomizer 251 of the post-processor 250. Herein, the multiplexing method may vary in accordance with various variables of the system design. One of the multiplexing methods of the packet formatter 240 consists of providing a burst section along a time axis, and, then, transmitting a plurality of data groups during a burst-on section within the burst section, and transmitting only the main service data during the burst-off section within the burst section. Herein, the burst section indicates the section starting from the beginning of the current burst until the beginning of the next burst.

At this point, the main service data may be transmitted during the burst-on section. The packet multiplexer 240 refers to the transmission parameter, such as information on the burst size or the burst period, so as to be informed of the number of data groups and the period of the data groups included in a single burst. Herein, the mobile service data and the main service data may co-exist in the burst-on section, and only the main service data may exist in the burst-off section. Therefore, a main data service section transmitting the main service data may exist in both burst-on and burst-off sections. At this point, the main data service section within the burst-on section and the number of main data service packets included in the burst-off section may either be different from one another or be the same.

When the mobile service data are transmitted in a burst structure, in the receiving system receiving only the mobile service data turns the power on only during the burst section, thereby receiving the corresponding data. Alternatively, in the section transmitting only the main service data, the power is turned off so that the main service data are not received in this section. Thus, the power consumption of the receiving system may be reduced.

Detailed Embodiments of the RS Frame Structure and Packet Multiplexing

Hereinafter, detailed embodiments of the pre-processor 230 and the packet multiplexer 240 will now be described. According to an embodiment of the present invention, the N value corresponding to the length of a row, which is included in the RS frame that is configured by the RS frame encoder 302, is set to 538. Accordingly, the RS frame encoder 302 receives 538 transport stream (TS) packets so as to configure a first RS frame having the size of 538*187 bytes. Thereafter, as described above, the first RS frame is processed with a (235,187)-RS encoding process so as to configure a second RS frame having the size of 538*235 bytes. Finally, the second RS frame is processed with generating a 16-bit checksum so as to configure a third RS frame having the sizes of 540*235.

Meanwhile, as shown in FIG. 6A, the sum of the number of bytes of regions A1 to A5 of region A, in which ½-rate encoded mobile service data are to be inserted, among the plurality of regions within the data group is equal to 13024 bytes (=2428+2580+2772+2472+2772 bytes). Herein, the number of byte prior to performing the ½-rate encoding process is equal to 6512 (=13024/2). On the other hand, the sum of the number of bytes of regions B1 and B2 of region B, in which ¼-rate encoded mobile service data are to be inserted, among the plurality of regions within the data group is equal to 2280 bytes (=930+1350 bytes). Herein, the number of byte prior to performing the ¼-rate encoding process is equal to 570 (=2280/4).

In other words, when 7082 bytes of mobile service data are inputted to the block processor 303, 6512 byte are expanded to 13024 bytes by being ½-rate encoded, and 570 bytes are expanded to 2280 bytes by being ¼-rate encoded. Thereafter, the block processor 303 inserts the mobile service data expanded to 13024 bytes in regions A1 to A5 of region A and, also, inserts the mobile service data expanded to 2280 bytes in regions B1 and B2 of region B. Herein, the 7082 bytes of mobile service data being inputted to the block processor 303 may be divided into an output of the RS frame encoder 302 and signaling information. In the present invention, among the 7082 bytes of mobile service data, 7050 bytes correspond to the output of the RS frame encoder 302, and the remaining 32 bytes correspond to the signaling information data. Then, ½-rate encoding or ¼-rate encoding is performed on the corresponding data bytes.

Meanwhile, a RS frame being processed with RS encoding and CRC encoding from the RS frame encoder 302 is configured of 540*235 bytes, in other words, 126900 bytes. The 126900 bytes are divided by 7050-byte units along the time axis, so as to produce 18 7050-byte units. Thereafter, a 32-byte unit of signaling information data is added to the 7050-byte unit mobile service data being outputted from the RS frame encoder 302. Subsequently, the RS frame encoder 302 performs ½-rate encoding or ¼-rate encoding on the corresponding data bytes, which are then outputted to the group formatter 304. Accordingly, the group formatter 304 inserts the ½-rate encoded data in region A and the ¼-rate encoded data in region B.

The process of deciding an N value that is required for configuring the RS frame from the RS frame encoder 302 will now be described in detail. More specifically, the size of the final RS frame (i.e., the third RS frame), which is RS encoded and CRC encoded from the RS frame encoder 302, which corresponds to (N+2)*235 bytes should be allocated to X number of groups, wherein X is an integer. Herein, in a single data group, 7050 data bytes prior to being encoded are allocated. Therefore, if the (N+2)*235 bytes are set to be the exact multiple of 7050(=30*235), the output data of the RS frame encoder 302 may be efficiently allocated to the data group. According to an embodiment of the present invention, the value of N is decided so that (N+2) becomes a multiple of 30. For example, in the present invention, N is equal to 538, and (N+2)(=540) divided by 30 is equal to 18. This indicates that the mobile service data within one RS frame are processed with either ½-rate encoding or ¼-rate encoding. The encoded mobile service data are then allocated to 18 data groups.

FIG. 7 illustrates a process of dividing the RS frame according to the present invention. More specifically, the RS frame having the size of (N+2)*235 is divided into 30*235 byte blocks. Then, the divided blocks are mapped to a single group. In other words, the data of a block having the size of 30*235 bytes are processed with one of a ½-rate encoding process and a ¼-rate encoding process and are, then, inserted in a data group. Thereafter, the data group having corresponding data and place holders inserted in each hierarchical region divided by the group formatter 304 passes through the data deinterleaver 305 and the packet formatter 306 so as to be inputted to the packet multiplexer 240.

FIG. 8 illustrates exemplary operations of a packet multiplexer for transmitting the data group according to the present invention. More specifically, the packet multiplexer 240 multiplexes a field including a data group, in which the mobile service data and main service data are mixed with one another, and a field including only the main service data. Thereafter, the packet multiplexer 240 outputs the multiplexed fields to the data randomizer 251. At this point, in order to transmit the RS frame having the size of 540*235 bytes, 18 data groups should be transmitted. Herein, each data group includes field synchronization data, as shown in FIG. 6A. Therefore, the 18 data groups are transmitted during 18 field sections, and the section during which the 18 data groups are being transmitted corresponds to the burst-on section.

In each field within the burst-on section, a data group including field synchronization data is multiplexed with main service data, which are then outputted. For example, in the embodiment of the present invention, in each field within the burst-on section, a data group having the size of 118 segments is multiplexed with a set of main service data having the size of 194 segments. Referring to FIG. 8, during the burst-on section (i.e., during the 18 field sections), a field including 18 data groups is transmitted. Then, during the burst-off section that follows (i.e., during the 12 field sections), a field consisting only of the main service data is transmitted. Subsequently, during a subsequent burst-on section, 18 fields including 18 data groups are transmitted. And, during the following burst-off section, 12 fields consisting only of the main service data are transmitted.

Furthermore, in the present invention, the same type of data service may be provided in the first burst-on section including the first 18 data groups and in the second burst-on section including the next 18 data groups. Alternatively, different types of data service may be provided in each burst-on section. For example, when it is assumed that different data service types are provided to each of the first burst-on section and the second burst-on section, and that the receiving system wishes to receive only one type of data service, the receiving system turns the power on only during the corresponding burst-on section including the desired data service type so as to receive the corresponding 18 data fields. Then, the receiving system turns the power off during the remaining 42 field sections so as to prevent other data service types from being received. Thus, the amount of power consumption of the receiving system may be reduced. In addition, the receiving system according to the present invention is advantageous in that one RS frame may be configured from the 18 data groups that are received during a single burst-on section.

According to the present invention, the number of data groups included in a burst-on section may vary based upon the size of the RS frame, and the size of the RS frame varies in accordance with the value N. More specifically, by adjusting the value N, the number of data groups within the burst section may be adjusted. Herein, in an example of the present invention, the (235,187)-RS encoding process adjusts the value N during a fixed state. Furthermore, the size of the mobile service data that can be inserted in the data group may vary based upon the sizes of the trellis initialization data or known data, the MPEG header, and the RS parity, which are inserted in the corresponding data group.

Meanwhile, since a data group including mobile service data in-between the data bytes of the main service data during the packet multiplexing process, the shifting of the chronological position (or place) of the main service data packet becomes relative. Also, a system object decoder (i.e., MPEG decoder) for processing the main service data of the receiving system, receives and decodes only the main service data and recognizes the mobile service data packet as a null data packet. Therefore, when the system object decoder of the receiving system receives a main service data packet that is multiplexed with the data group, a packet jitter occurs.

At this point, since a multiple-level buffer for the video data exists in the system object decoder and the size of the buffer is relatively large, the packet jitter generated from the packet multiplexer 240 does not cause any serious problem in case of the video data. However, since the size of the buffer for the audio data is relatively small, the packet jitter may cause considerable problem. More specifically, due to the packet jitter, an overflow or underflow may occur in the buffer for the main service data of the receiving system (e.g., the buffer for the audio data). Therefore, the packet jitter mitigator 220 re-adjusts the relative position of the main service data packet so that the overflow or underflow does not occur in the system object decoder.

In the present invention, examples of repositioning places for the audio data packets within the main service data in order to minimize the influence on the operations of the audio buffer will be described in detail. The packet jitter mitigator 220 repositions the audio data packets in the main service data section so that the audio data packets of the main service data can be as equally and uniformly aligned and positioned as possible. The standard for repositioning the audio data packets in the main service data performed by the packet jitter mitigator 220 will now be described. Herein, it is assumed that the packet jitter mitigator 220 knows the same multiplexing information as that of the packet multiplexer 240, which is placed further behind the packet jitter mitigator 220.

Firstly, if one audio data packet exists in the main service data section (e.g., the main service data section positioned between two data groups) within the burst-on section, the audio data packet is positioned at the very beginning of the main service data section. Alternatively, if two audio data packets exist in the corresponding data section, one audio data packet is positioned at the very beginning and the other audio data packet is positioned at the very end of the main service data section. Further, if more than three audio data packets exist, one audio data packet is positioned at the very beginning of the main service data section, another is positioned at the very end of the main service data section, and the remaining audio data packets are equally positioned between the first and last audio data packets. Secondly, during the main service data section placed immediately before the beginning of a burst-on section (i.e., during a burst-off section), the audio data packet is placed at the very end of the corresponding section.

Thirdly, during a main service data section within the burst-off section after the burst-on section, the audio data packet is positioned at the very end of the main service data section. Finally, the data packets other than audio data packets are positioned in accordance with the inputted order in vacant spaces (i.e., spaces that are not designated for the audio data packets). Meanwhile, when the positions of the main service data packets are relatively re-adjusted, associated program clock reference (PCR) values may also be modified accordingly. The PCR value corresponds to a time reference value for synchronizing the time of the MPEG decoder. Herein, the PCR value is inserted in a specific region of a TS packet and then transmitted.

In the example of the present invention, the packet jitter mitigator 220 also performs the operation of modifying the PCR value. The output of the packet jitter mitigator 220 is inputted to the packet multiplexer 240. As described above, the packet multiplexer 240 multiplexes the main service data packet outputted from the packet jitter mitigator 220 with the mobile service data packet outputted from the pre-processor 230 into a burst structure in accordance with a pre-determined multiplexing rule. Then, the packet multiplexer 240 outputs the multiplexed data packets to the data randomizer 251 of the post-processor 250.

If the inputted data correspond to the main service data packet, the data randomizer 251 performs the same randomizing process as that of the conventional randomizer. More specifically, the synchronization byte within the main service data packet is deleted. Then, the remaining 187 data bytes are randomized by using a pseudo random byte generated from the data randomizer 251. Thereafter, the randomized data are outputted to the RS encoder/non-systematic RS encoder 252.

On the other hand, if the inputted data correspond to the mobile service data packet, the data randomizer 251 may randomize only a portion of the data packet. For example, if it is assumed that a randomizing process has already been performed in advance on the mobile service data packet by the pre-processor 230, the data randomizer 251 deletes the synchronization byte from the 4-byte MPEG header included in the mobile service data packet and, then, performs the randomizing process only on the remaining 3 data bytes of the MPEG header. Thereafter, the randomized data bytes are outputted to the RS encoder/non-systematic RS encoder 252. More specifically, the randomizing process is not performed on the remaining portion of the mobile service data excluding the MPEG header. In other words, the remaining portion of the mobile service data packet is directly outputted to the RS encoder/non-systematic RS encoder 252 without being randomized. Also, the data randomizer 251 may or may not perform a randomizing process on the known data (or known data place holders) and the initialization data place holders included in the mobile service data packet.

The RS encoder/non-systematic RS encoder 252 performs an RS encoding process on the data being randomized by the data randomizer 251 or on the data bypassing the data randomizer 251, so as to add 20 bytes of RS parity data. Thereafter, the processed data are outputted to the data interleaver 253. Herein, if the inputted data correspond to the main service data packet, the RS encoder/non-systematic RS encoder 252 performs the same systematic RS encoding process as that of the conventional broadcasting system, thereby adding the 20-byte RS parity data at the end of the 187-byte data. Alternatively, if the inputted data correspond to the mobile service data packet, the RS encoder/non-systematic RS encoder 252 performs a non-systematic RS encoding process. At this point, the 20-byte RS parity data obtained from the non-systematic RS encoding process are inserted in a pre-decided parity byte place within the mobile service data packet.

The data interleaver 253 corresponds to a byte unit convolutional interleaver. The output of the data interleaver 253 is inputted to the parity replacer 254 and to the non-systematic RS encoder 255. Meanwhile, a process of initializing a memory within the trellis encoding module 256 is primarily required in order to decide the output data of the trellis encoding module 256, which is located after the parity replacer 254, as the known data pre-defined according to an agreement between the receiving system and the transmitting system. More specifically, the memory of the trellis encoding module 256 should first be initialized before the received known data sequence is trellis-encoded. At this point, the beginning portion of the known data sequence that is received corresponds to the initialization data place holder and not to the actual known data. Herein, the initialization data place holder has been included in the data by the group formatter within the pre-processor 230 in an earlier process. Therefore, the process of generating initialization data and replacing the initialization data place holder of the corresponding memory with the generated initialization data are required to be performed immediately before the inputted known data sequence is trellis-encoded.

Additionally, a value of the trellis memory initialization data is decided and generated based upon a memory status of the trellis encoding module 256. Further, due to the newly replaced initialization data, a process of newly calculating the RS parity and replacing the RS parity, which is outputted from the data interleaver 253, with the newly calculated RS parity is required. Therefore, the non-systematic RS encoder 255 receives the mobile service data packet including the initialization data place holders, which are to be replaced with the actual initialization data, from the data interleaver 253 and also receives the initialization data from the trellis encoding module 256.

Among the inputted mobile service data packet, the initialization data place holders are replaced with the initialization data, and the RS parity data that are added to the mobile service data packet are removed and processed with non-systematic RS encoding. Thereafter, the new RS parity obtained by performing the non-systematic RS encoding process is outputted to the parity replacer 255. Accordingly, the parity replacer 255 selects the output of the data interleaver 253 as the data within the mobile service data packet, and the parity replacer 255 selects the output of the non-systematic RS encoder 255 as the RS parity. The selected data are then outputted to the trellis encoding module 256.

Meanwhile, if the main service data packet is inputted or if the mobile service data packet, which does not include any initialization data place holders that are to be replaced, is inputted, the parity replacer 254 selects the data and RS parity that are outputted from the data interleaver 253. Then, the parity replacer 254 directly outputs the selected data to the trellis encoding module 256 without any modification. The trellis encoding module 256 converts the byte-unit data to symbol units and performs a 12-way interleaving process so as to trellis-encode the received data. Thereafter, the processed data are outputted to the synchronization multiplexer 260.

The synchronization multiplexer 260 inserts a field synchronization signal and a segment synchronization signal to the data outputted from the trellis encoding module 256 and, then, outputs the processed data to the pilot inserter 271 of the transmission unit 270. Herein, the data having a pilot inserted therein by the pilot inserter 271 are modulated by the modulator 272 in accordance with a pre-determined modulating method (e.g., a VSB method). Thereafter, the modulated data are transmitted to each receiving system though the radio frequency (RF) up-converter 273.

Block Processor

FIG. 9 illustrates a block diagram showing a structure of a block processor according to the present invention. Herein, the block processor includes a byte-bit converter 401, a symbol encoder 402, a symbol interleaver 403, and a symbol-byte converter 404. The byte-bit converter 401 divides the mobile service data bytes that are inputted from the RS frame encoder 112 into bits, which are then outputted to the symbol encoder 402. The byte-bit converter 401 may also receive signaling information including transmission parameters. The signaling information data bytes are also divided into bits so as to be outputted to the symbol encoder 402. Herein, the signaling information including transmission parameters may be processed with the same data processing step as that of the mobile service data. More specifically, the signaling information may be inputted to the block processor 303 by passing through the data randomizer 301 and the RS frame encoder 302. Alternatively, the signaling information may also be directly outputted to the block processor 303 without passing though the data randomizer 301 and the RS frame encoder 302.

The symbol encoder 402 corresponds to a G/H-rate encoder encoding the inputted data from G bits to H bits and outputting the data encoded at the coding rate of G/H. According to the embodiment of the present invention, it is assumed that the symbol encoder 402 performs either a coding rate of ½ (also referred to as a ½-rate encoding process) or an encoding process at a coding rate of ¼ (also referred to as a ¼-rate encoding process). The symbol encoder 402 performs one of ½-rate encoding and ¼-rate encoding on the inputted mobile service data and signaling information. Thereafter, the signaling information is also recognized as the mobile service data and processed accordingly.

In case of performing the ½-rate coding process, the symbol encoder 402 receives 1 bit and encodes the received 1 bit to 2 bits (i.e., 1 symbol). Then, the symbol encoder 402 outputs the processed 2 bits (or 1 symbol). On the other hand, in case of performing the ¼-rate encoding process, the symbol encoder 402 receives 1 bit and encodes the received 1 bit to 4 bits (i.e., 2 symbols). Then, the symbol encoder 402 outputs the processed 4 bits (or 2 symbols).

FIG. 10 illustrates a detailed block diagram of the symbol encoder 402 shown in FIG. 9. The symbol encoder 402 includes two delay units 501 and 503 and three adders 502, 504, and 505. Herein, the symbol encoder 402 encodes an input data bit U and outputs the coded bit U to 4 bits (u0 to u4). At this point, the data bit U is directly outputted as uppermost bit u0 and simultaneously encoded as lower bit u1u2u3 and then outputted. More specifically, the input data bit U is directly outputted as the uppermost bit u0 and simultaneously outputted to the first and third adders 502 and 505. The first adder 502 adds the input data bit U and the output bit of the first delay unit 501 and, then, outputs the added bit to the second delay unit 503. Then, the data bit delayed by a pre-determined time (e.g., by 1 clock) in the second delay unit 503 is outputted as lower bit u1 and simultaneously fed-back to the first delay unit 501. The first delay unit 501 delays the data bit fed-back from the second delay unit 503 by a pre-determined time (e.g., by 1 clock). Then, the first delay unit 501 outputs the delayed data bit to the first adder 502 and the second adder 504. The second adder 504 adds the data bits outputted from the first and second delay units 501 and 503 as a lower bit u2. The third adder 505 adds the input data bit U and the output of the second delay unit 503 and outputs the added data bit as a lower bit u3.

At this point, if the input data bit U corresponds to data encoded at a ½-coding rate, the symbol encoder 402 configures a symbol with u1u0 bits from the 4 output bits u0u1u2u3. Then, the symbol encoder 402 outputs the newly configured symbol. Alternatively, if the input data bit U corresponds to data encoded at a ¼-coding rate, the symbol encoder 402 configures and outputs a symbol with bits u1u0 and, then, configures and outputs another symbol with bits u2u3. According to another embodiment of the present invention, if the input data bit U corresponds to data encoded at a ¼-coding rate, the symbol encoder 402 may also configure and output a symbol with bits u1u0, and then repeat the process once again and output the corresponding bits. According to yet another embodiment of the present invention, the symbol encoder outputs all four output bits U u0u1u2u3. Then, when using the ½-coding rate, the symbol interleaver 403 located behind the symbol encoder 402 selects only the symbol configured of bits u1u0 from the four output bits u0u1u2u3. Alternatively, when using the ¼-coding rate, the symbol interleaver 403 may select the symbol configured of bits u1u0 and then select another symbol configured of bits u2u3. According to another embodiment, when using the ¼-coding rate, the symbol interleaver 403 may repeatedly select the symbol configured of bits u1u0.

The output of the symbol encoder 402 is inputted to the symbol interleaver 403. Then, the symbol interleaver 403 performs block interleaving in symbol units on the data outputted from the symbol encoder 402. Any interleaver performing structural rearrangement (or realignment) may be applied as the symbol interleaver 403 of the block processor. However, in the present invention, a variable length symbol interleaver that can be applied even when a plurality of lengths is provided for the symbol, so that its order may be rearranged, may also be used.

FIG. 11 illustrates a symbol interleaver according to an embodiment of the present invention. Herein, the symbol interleaver according to the embodiment of the present invention corresponds to a variable length symbol interleaver that may be applied even when a plurality of lengths is provided for the symbol, so that its order may be rearranged. Particularly, FIG. 11 illustrates an example of the symbol interleaver when K=6 and L=8. Herein, K indicates a number of symbols that are outputted for symbol interleaving from the symbol encoder 402. And, L represents a number of symbols that are actually interleaved by the symbol interleaver 403.

In the present invention, the symbol interleaver 403 should satisfy the conditions of L=2^(n) (wherein n is an integer) and of L≧K. If there is a difference in value between K and L, (L−K) number of null (or dummy) symbols is added, thereby creating an interleaving pattern. Therefore, K becomes a block size of the actual symbols that are inputted to the symbol interleaver 403 in order to be interleaved. L becomes an interleaving unit when the interleaving process is performed by an interleaving pattern created from the symbol interleaver 403. The example of what is described above is illustrated in FIG. 11.

More specifically, FIG. 11( a) to FIG. 11( c) illustrate a variable length interleaving process of a symbol interleaver shown in FIG. 9. The number of symbols outputted from the symbol encoder 402 in order to be interleaved is equal to 6 (i.e., K=6). In other words, 6 symbols are outputted from the symbol encoder 402 in order to be interleaved. And, the actual interleaving unit (L) is equal to 8 symbols. Therefore, as shown in FIG. 11( a), 2 symbols are added to the null (or dummy) symbol, thereby creating the interleaving pattern. Equation 2 shown below described the process of sequentially receiving K number of symbols, the order of which is to be rearranged, and obtaining an L value satisfying the conditions of L=2^(n) (wherein n is an integer) and of L≧K, thereby creating the interleaving so as to realign (or rearrange) the symbol order.

In relation to all places, wherein 0≦i≦L−1, P(i)={S×i×(i+1)/2}mod L  Equation 2

Herein, L≧K, L=2^(n), and n and S are integers. Referring to FIG. 11, it is assumed that S is equal to 89, and that L is equal to 8, and FIG. 11 illustrates the created interleaving pattern and an example of the interleaving process. As shown in FIG. 11( b), the order of K number of input symbols and (L−K) number of null symbols is rearranged by using the above-mentioned Equation 2. Then, as shown in FIG. 11( c), the null byte places are removed, so as to rearrange the order, by using Equation 3 shown below. Thereafter, the symbol that is interleaved by the rearranged order is then outputted to the symbol-byte converter. if P(i)>K−1, then P(i) place is removed and rearranged  Equation 3

Subsequently, the symbol-byte converter 404 converts to bytes the mobile service data symbols, having the rearranging of the symbol order completed and then outputted in accordance with the rearranged order, and thereafter outputs the converted bytes to the group formatter 304.

FIG. 12A illustrates a block diagram showing the structure of a block processor according to another embodiment of the present invention. Herein, the block processor includes an interleaving unit 610 and a block formatter 620. The interleaving unit 610 may include a byte-symbol converter 611, a symbol-byte converter 612, a symbol interleaver 613, and a symbol-byte converter 614. Herein, the symbol interleaver 613 may also be referred to as a block interleaver.

The byte-symbol converter 611 of the interleaving unit 610 converts the mobile service data X outputted in byte units from the RS frame encoder 302 to symbol units. Then, the byte-symbol converter 611 outputs the converted mobile service data symbols to the symbol-byte converter 612 and the symbol interleaver 613. More specifically, the byte-symbol converter 611 converts each 2 bits of the inputted mobile service data byte (=8 bits) to 1 symbol and outputs the converted symbols. This is because the input data of the trellis encoding module 256 consist of symbol units configured of 2 bits. The relationship between the block processor 303 and the trellis encoding module 256 will be described in detail in a later process. At this point, the byte-symbol converter 611 may also receive signaling information including transmission parameters. Furthermore, the signaling information bytes may also be divided into symbol units and then outputted to the symbol-byte converter 612 and the symbol interleaver 613.

The symbol-byte converter 612 groups 4 symbols outputted from the byte-symbol converter 611 so as to configure a byte. Thereafter, the converted data bytes are outputted to the block formatter 620. Herein, each of the symbol-byte converter 612 and the byte-symbol converter 611 respectively performs an inverse process on one another. Therefore, the yield of these two blocks is offset. Accordingly, as shown in FIG. 12B, the input data X bypass the byte-symbol converter 611 and the symbol-byte converter 612 and are directly inputted to the block formatter 620. More specifically, the interleaving unit 610 of FIG. 12B has a structure equivalent to that of the interleaving unit shown in FIG. 12A. Therefore, the same reference numerals will be used in FIG. 12A and FIG. 12B.

The symbol interleaver 613 performs block interleaving in symbol units on the data that are outputted from the byte-symbol converter 611. Subsequently, the symbol interleaver 613 outputs the interleaved data to the symbol-byte converter 614. Herein, any type of interleaver that can rearrange the structural order may be used as the symbol interleaver 613 of the present invention. In the example given in the present invention, a variable length interleaver that may be applied for symbols having a wide range of lengths, the order of which is to be rearranged. For example, the symbol interleaver of FIG. 11 may also be used in the block processor shown in FIG. 12A and FIG. 12B.

The symbol-byte converter 614 outputs the symbols having the rearranging of the symbol order completed, in accordance with the rearranged order. Thereafter, the symbols are grouped to be configured in byte units, which are then outputted to the block formatter 620. More specifically, the symbol-byte converter 614 groups 4 symbols outputted from the symbol interleaver 613 so as to configure a data byte. As shown in FIG. 13, the block formatter 620 performs the process of aligning the output of each symbol-byte converter 612 and 614 within the block in accordance with a set standard. Herein, the block formatter 620 operates in association with the trellis encoding module 256.

More specifically, the block formatter 620 decides the output order of the mobile service data outputted from each symbol-byte converter 612 and 614 while taking into consideration the place (or order) of the data excluding the mobile service data that are being inputted, wherein the mobile service data include main service data, known data, RS parity data, and MPEG header data.

According to the embodiment of the present invention, the trellis encoding module 256 is provided with 12 trellis encoders. FIG. 14 illustrates a block diagram showing the trellis encoding module 256 according to the present invention. In the example shown in FIG. 14, 12 identical trellis encoders are combined to the interleaver in order to disperse noise. Herein, each trellis encoder may be provided with a pre-coder.

FIG. 15A illustrates the block processor 303 being concatenated with the trellis encoding module 256. In the transmitting system, a plurality of blocks actually exists between the pre-processor 230 including the block processor 303 and the trellis encoding module 256, as shown in FIG. 3. Conversely, the receiving system considers the pre-processor 230 to be concatenated with the trellis encoding module 256, thereby performing the decoding process accordingly. However, the data excluding the mobile service data that are being inputted to the trellis encoding module 256, wherein the mobile service data include main service data, known data, RS parity data, and MPEG header data, correspond to data that are added to the blocks existing between the block processor 303 and the trellis encoding module 256. FIG. 15B illustrates an example of a data processor 650 being positioned between the block processor 303 and the trellis encoding module 256, while taking the above-described instance into consideration.

Herein, when the interleaving unit 610 of the block processor 303 performs a ½-rate encoding process, the interleaving unit 610 may be configured as shown in FIG. 12A (or FIG. 12B). Referring to FIG. 3, for example, the data processor 650 may include a group formatter 304, a data deinterleaver 305, a packet formatter 306, a packet multiplexer 240, and a post-processor 250, wherein the post-processor 250 includes a data randomizer 251, a RS encoder/non-systematic RS encoder 252, a data interleaver 253, a parity replacer 254, and a non-systematic RS encoder 255.

At this point, the trellis encoding module 256 symbolizes the data that are being inputted so as to divide the symbolized data and to send the divided data to each trellis encoder in accordance with a pre-defined method. Herein, one byte is converted into 4 symbols, each being configured of 2 bits. Also, the symbols created from the single data byte are all transmitted to the same trellis encoder. Accordingly, each trellis encoder pre-codes an upper bit of the input symbol, which is then outputted as the uppermost output bit C2. Alternatively, each trellis encoder trellis-encodes a lower bit of the input symbol, which is then outputted as two output bits C1 and C0. The block formatter 620 is controlled so that the data byte outputted from each symbol-byte converter can be transmitted to different trellis encoders.

Hereinafter, the operation of the block formatter 620 will now be described in detail with reference to FIG. 9 to FIG. 12. Referring to FIG. 12A, for example, the data byte outputted from the symbol-byte converter 612 and the data byte outputted from the symbol-byte converter 614 are inputted to different trellis encoders of the trellis encoding module 256 in accordance with the control of the block formatter 620. Hereinafter, the data byte outputted from the symbol-byte converter 612 will be referred to as X, and the data byte outputted from the symbol-byte converter 614 will be referred to as Y, for simplicity. Referring to FIG. 13( a), each number (i.e., 0 to 11) indicates the first to twelfth trellis encoders of the trellis encoding module 256, respectively.

In addition, the output order of both symbol-byte converters are arranged (or aligned) so that the data bytes outputted from the symbol-byte converter 612 are respectively inputted to the 0^(th) to 5^(th) trellis encoders (0 to 5) of the trellis encoding module 256, and that the data bytes outputted from the symbol-byte converter 614 are respectively inputted to the 6^(th) to 11^(th) trellis encoders (6 to 11) of the trellis encoding module 256. Herein, the trellis encoders having the data bytes outputted from the symbol-byte converter 612 allocated therein, and the trellis encoders having the data bytes outputted from the symbol-byte converter 614 allocated therein are merely examples given to simplify the understanding of the present invention. Furthermore, according to an embodiment of the present invention, and assuming that the input data of the block processor 303 correspond to a block configured of 12 bytes, the symbol-byte converter 612 outputs 12 data bytes from X0 to X11, and the symbol-byte converter 614 outputs 12 data bytes from Y0 to Y11.

FIG. 13( b) illustrates an example of data being inputted to the trellis encoding module 256. Particularly, FIG. 13( b) illustrates an example of not only the mobile service data but also the main service data and RS parity data being inputted to the trellis encoding module 256, so as to be distributed to each trellis encoder. More specifically, the mobile service data outputted from the block processor 303 pass through the group formatter 304, from which the mobile service data are mixed with the main service data and RS parity data and then outputted, as shown in FIG. 13 (a). Accordingly, each data byte is respectively inputted to the 12 trellis encoders in accordance with the positions (or places) within the data group after being data-interleaved.

Herein, when the output data bytes X and Y of the symbol-byte converters 612 and 614 are allocated to each respective trellis encoder, the input of each trellis encoder may be configured as shown in FIG. 13( b). More specifically, referring to FIG. 13( b), the six mobile service data bytes (X0 to X5) outputted from the symbol-byte converter 612 are sequentially allocated (or distributed) to the first to sixth trellis encoders (0 to 5) of the trellis encoding module 256. Also, the 2 mobile service data bytes Y0 and Y1 outputted from the symbol-byte converter 614 are sequentially allocated to the 7^(th) and 8^(th) trellis encoders (6 and 7) of the trellis encoding module 256. Thereafter, among the 5 main service data bytes, 4 data bytes are sequentially allocated to the 9^(th) and 12^(th) trellis encoders (8 to 11) of the trellis encoding module 256. Finally, the remaining 1 byte of the main service data byte is allocated once again to the first trellis encoder (0).

It is assumed that the mobile service data, the main service data, and the RS parity data are allocated to each trellis encoder, as shown in FIG. 13( b). It is also assumed that, as described above, the input of the block processor 303 is configured of 12 bytes, and that 12 bytes from X0 to X1 are outputted from the symbol-byte converter 612, and that 12 bytes from Y0 to Y11 are outputted from the symbol-byte converter 614. In this case, as shown in FIG. 13( c), the block formatter 620 arranges the data bytes that are to be outputted from the symbol-byte converters 612 and 614 by the order of X0 to X5, Y0, Y1, X6 to X10, Y2 to Y7, X1, and Y8 to Y11. More specifically, the trellis encoder that is to perform the encoding process is decided based upon the position (or place) within the transmission frame in which each data byte is inserted. At this point, not only the mobile service data but also the main service data, the MPEG header data, and the RS parity data are also inputted to the trellis encoding module 256. Herein, it is assumed that, in order to perform the above-described operation, the block formatter 620 is informed of (or knows) the information on the data group format after the data-interleaving process.

FIG. 16 illustrates a block diagram of the block processor performing an encoding process at a coding rate of 1/N according to an embodiment of the present invention. Herein, the block processor includes (N−1) number of symbol interleavers 741 to 74N−1, which are configured in a parallel structure. More specifically, the block processor having the coding rate of 1/N consists of a total of N number of branches (or paths) including a branch (or path), which is directly transmitted to the block formatter 730. In addition, the symbol interleaver 741 to 74N−1 of each branch may each be configured of a different symbol interleaver. Furthermore, (N−1) number of symbol-byte converter 751 to 75N−1 each corresponding to each (N−1) number of symbol interleavers 741 to 74N−1 may be included at the end of each symbol interleaver, respectively. Herein, the output data of the (N−1) number of symbol-byte converter 751 to 75N−1 are also inputted to the block formatter 730.

In the example of the present invention, N is equal to or smaller than 12. If N is equal to 12, the block formatter 730 may align the output data so that the output byte of the 12^(th) symbol-byte converter 75N−1 is inputted to the 12^(th) trellis encoder. Alternatively, if N is equal to 3, the block formatter 730 may arranged the output order, so that the data bytes outputted from the symbol-byte converter 720 are inputted to the 1^(st) to 4^(th) trellis encoders of the trellis encoding module 256, and that the data bytes outputted from the symbol-byte converter 751 are inputted to the 5^(th) to 8^(th) trellis encoders, and that the data bytes outputted from the symbol-byte converter 752 are inputted to the 9^(th) to 12^(th) trellis encoders. At this point, the order of the data bytes outputted from each symbol-byte converter may vary in accordance with the position within the data group of the data other than the mobile service data, which are mixed with the mobile service data that are outputted from each symbol-byte converter.

FIG. 17 illustrates a detailed block diagram showing the structure of a block processor according to another embodiment of the present invention. Herein, the block formatter is removed from the block processor so that the operation of the block formatter may be performed by a group formatter. More specifically, the block processor of FIG. 17 may include a byte-symbol converter 810, symbol-byte converters 820 and 840, and a symbol interleaver 830. In this case, the output of each symbol-byte converter 820 and 840 is inputted to the group formatter 850.

Also, the block processor may obtain a desired coding rate by adding symbol interleavers and symbol-byte converters. If the system designer wishes a coding rate of 1/N, the block processor needs to be provided with a total of N number of branches (or paths) including a branch (or path), which is directly transmitted to the block formatter 850, and (N−1) number of symbol interleavers and symbol-byte converters configured in a parallel structure with (N−1) number of branches. At this point, the group formatter 850 inserts place holders ensuring the positions (or places) for the MPEG header, the non-systematic RS parity, and the main service data. And, at the same time, the group formatter 850 positions the data bytes outputted from each branch of the block processor.

The number of trellis encoders, the number of symbol-byte converters, and the number of symbol interleavers proposed in the present invention are merely exemplary. And, therefore, the corresponding numbers do not limit the spirit or scope of the present invention. It is apparent to those skilled in the art that the type and position of each data byte being allocated to each trellis encoder of the trellis encoding module 256 may vary in accordance with the data group format. Therefore, the present invention should not be understood merely by the examples given in the description set forth herein. The mobile service data that are encoded at a coding rate of 1/N and outputted from the block processor 303 are inputted to the group formatter 304. Herein, in the example of the present invention, the order of the output data outputted from the block formatter of the block processor 303 are aligned and outputted in accordance with the position of the data bytes within the data group.

Signaling Information Processing

The transmitter 200 according to the present invention may insert transmission parameters by using a plurality of methods and in a plurality of positions (or places), which are then transmitted to the receiving system. For simplicity, the definition of a transmission parameter that is to be transmitted from the transmitter to the receiving system will now be described. The transmission parameter includes data group information, region information within a data group, the number of RS frames configuring a super frame (i.e., a super frame size (SFS)), the number of RS parity data bytes (P) for each column within the RS frame, whether or not a checksum, which is added to determine the presence of an error in a row direction within the RS frame, has been used, the type and size of the checksum if the checksum is used (presently, 2 bytes are added to the CRC), the number of data groups configuring one RS frame—since the RS frame is transmitted to one burst section, the number of data groups configuring the one RS frame is identical to the number of data groups within one burst (i.e., burst size (BS)), a turbo code mode, and a RS code mode.

Also, the transmission parameter required for receiving a burst includes a burst period—herein, one burst period corresponds to a value obtained by counting the number of fields starting from the beginning of a current burst until the beginning of a next burst, a positioning order of the RS frames that are currently being transmitted within a super frame (i.e., a permuted frame index (PFI)) or a positioning order of groups that are currently being transmitted within a RS frame (burst) (i.e., a group index (GI)), and a burst size. Depending upon the method of managing a burst, the transmission parameter also includes the number of fields remaining until the beginning of the next burst (i.e., time to next burst (TNB)). And, by transmitting such information as the transmission parameter, each data group being transmitted to the receiving system may indicate a relative distance (or number of fields) between a current position and the beginning of a next burst.

The information included in the transmission parameter corresponds to examples given to facilitate the understanding of the present invention. Therefore, the proposed examples do not limit the scope or spirit of the present invention and may be easily varied or modified by anyone skilled in the art. According to the first embodiment of the present invention, the transmission parameter may be inserted by allocating a predetermined region of the mobile service data packet or the data group. In this case, the receiving system performs synchronization and equalization on a received signal, which is then decoded by symbol units. Thereafter, the packet deformatter may separate the mobile service data and the transmission parameter so as to detect the transmission parameter. According to the first embodiment, the transmission parameter may be inserted from the group formatter 304 and then transmitted.

According to the second embodiment of the present invention, the transmission parameter may be multiplexed with another type of data. For example, when known data are multiplexed with the mobile service data, a transmission parameter may be inserted, instead of the known data, in a place (or position) where a known data byte is to be inserted. Alternatively, the transmission parameter may be mixed with the known data and then inserted in the place where the known data byte is to be inserted. According to the second embodiment, the transmission parameter may be inserted from the group formatter 304 or from the packet formatter 306 and then transmitted.

According to a third embodiment of the present invention, the transmission parameter may be inserted by allocating a portion of a reserved region within a field synchronization segment of a transmission frame. In this case, since the receiving system may perform decoding on a receiving signal by symbol units before detecting the transmission parameter, the transmission parameter having information on the processing methods of the block processor 303 and the group formatter 304 may be inserted in a reserved field of a field synchronization signal. More specifically, the receiving system obtains field synchronization by using a field synchronization segment so as to detect the transmission parameter from a pre-decided position. According to the third embodiment, the transmission parameter may be inserted from the synchronization multiplexer 240 and then transmitted.

According to the fourth embodiment of the present invention, the transmission parameter may be inserted in a layer (or hierarchical region) higher than a transport stream (TS) packet. In this case, the receiving system should be able to receive a signal and process the received signal to a layer higher than the TS packet in advance. At this point, the transmission parameter may be used to certify the transmission parameter of a currently received signal and to provide the transmission parameter of a signal that is to be received in a later process.

In the present invention, the variety of transmission parameters associated with the transmission signal may be inserted and transmitted by using the above-described methods according to the first to fourth embodiment of the present invention. At this point, the transmission parameter may be inserted and transmitted by using only one of the four embodiments described above, or by using a selection of the above-described embodiments, or by using all of the above-described embodiments. Furthermore, the information included in the transmission parameter may be duplicated and inserted in each embodiment. Alternatively, only the required information may be inserted in the corresponding position of the corresponding embodiment and then transmitted. Furthermore, in order to ensure robustness of the transmission parameter, a block encoding process of a short cycle (or period) may be performed on the transmission parameter and, then, inserted in a corresponding region. The method for performing a short-period block encoding process on the transmission parameter may include, for example, Kerdock encoding, BCH encoding, RS encoding, and repetition encoding of the transmission parameter. Also, a combination of a plurality of block encoding methods may also be performed on the transmission parameter.

The transmission parameters may be grouped to create a block code of a small size, so as to be inserted in a byte place allocated within the data group for signaling and then transmitted. However, in this case, the block code passes through the block decoded from the receiving end so as to obtain a transmission parameter value. Therefore, the transmission parameters of the turbo code mode and the RS code mode, which are required for block decoding, should first be obtained. Accordingly, the transmission parameters associated with a particular mode may be inserted in a specific section of a known data region. And, in this case, a correlation of with a symbol may be used for a faster decoding process. The receiving system refers to the correlation between each sequence and the currently received sequences, thereby determining the encoding mode and the combination mode.

Meanwhile, when the transmission parameter is inserted in the field synchronization segment region or the known data region and then transmitted, and when the transmission parameter has passed through the transmission channel, the reliability of the transmission parameter is deteriorated. Therefore, one of a plurality of pre-defined patterns may also be inserted in accordance with the corresponding transmission parameter. Herein, the receiving system performs a correlation calculation between the received signal and the pre-defined patterns so as to recognize the transmission parameter. For example, it is assumed that a burst including 5 data groups is pre-decided as pattern A based upon an agreement between the transmitting system and the receiving system. In this case, the transmitting system inserts and transmits pattern A, when the number of groups within the burst is equal to 5. Thereafter, the receiving system calculates a correlation between the received data and a plurality of reference patterns including pattern A, which was created in advance. At this point, if the correlation value between the received data and pattern A is the greatest, the received data indicates the corresponding parameter, and most particularly, the number of groups within the burst. At this point, the number of groups may be acknowledged as 5. Hereinafter, the process of inserting and transmitting the transmission parameter will now be described according to first, second, and third embodiments of the present invention.

First Embodiment

FIG. 18 illustrates a schematic diagram of the group formatter 304 receiving the transmission parameter and inserting the received transmission parameter in region A of the data group according to the present invention. Herein, the group formatter 304 receives mobile service data from the block processor 303. Conversely, the transmission parameter is processed with at least one of a data randomizing process, a RS frame encoding process, and a block processing process, and may then be inputted to the group formatter 304. Alternatively, the transmission parameter may be directly inputted to the group formatter 304 without being processed with any of the above-mentioned processes. In addition, the transmission parameter may be provided from the service multiplexer 100. Alternatively, the transmission parameter may also be generated and provided from within the transmitter 200. The transmission parameter may also include information required by the receiving system in order to receive and process the data included in the data group. For example, the transmission parameter may include data group information, and multiplexing information.

The group formatter 304 inserts the mobile service data and transmission parameter which are to be inputted to corresponding regions within the data group in accordance with a rule for configuring a data group. For example, the transmission parameter passes through a block encoding process of a short period and is, then, inserted in region A of the data group. Particularly, the transmission parameter may be inserted in a pre-arranged and arbitrary position (or place) within region A. If it is assumed that the transmission parameter has been block encoded by the block processor 303, the block processor 303 performs the same data processing operation as the mobile service data, more specifically, either a ½-rate encoding or ¼-rate encoding process on the signaling information including the transmission parameter. Thereafter, the block processor 303 outputs the processed transmission parameter to the group formatter 304. Thereafter, the signaling information is also recognized as the mobile service data and processed accordingly.

FIG. 19 illustrates a block diagram showing an example of the block processor receiving the transmission parameter and processing the received transmission parameter with the same process as the mobile service data. Particularly, FIG. 19 illustrates an example showing the structure of FIG. 9 further including a signaling information provider 411 and multiplexer 412. More specifically, the signaling information provider 411 outputs the signaling information including the transmission parameter to the multiplexer 412. The multiplexer 412 multiplexes the signaling information and the output of the RS frame encoder 302. Then, the multiplexer 412 outputs the multiplexed data to the byte-bit converter 401.

The byte-bit converter 401 divides the mobile service data bytes or signaling information byte outputted from the multiplexer 412 into bits, which are then outputted to the symbol encoder 402. The subsequent operations are identical to those described in FIG. 9. Therefore, a detailed description of the same will be omitted for simplicity. If any of the detailed structures of the block processor 303 shown in FIG. 12, FIG. 15, FIG. 16, and FIG. 17, the signaling information provider 411 and the multiplexer 412 may be provided behind the byte-symbol converter.

Second Embodiment

Meanwhile, when known data generated from the group formatter in accordance with a pre-decided rule are inserted in a corresponding region within the data group, a transmission parameter may be inserted in at least a portion of a region, where known data may be inserted, instead of the known data. For example, when a long known data sequence is inserted at the beginning of region A within the data group, a transmission parameter may be inserted in at least a portion of the beginning of region A instead of the known data. A portion of the known data sequence that is inserted in the remaining portion of region A, excluding the portion in which the transmission parameter is inserted, may be used to detect a starting point of the data group by the receiving system. Alternatively, another portion of region A may be used for channel equalization by the receiving system.

In addition, when the transmission parameter is inserted in the known data region instead of the actual known data. The transmission parameter may be block encoded in short periods and then inserted. Also, as described above, the transmission parameter may also be inserted based upon a pre-defined pattern in accordance with the transmission parameter. If the group formatter 304 inserts known data place holders in a region within the data group, wherein known data may be inserted, instead of the actual known data, the transmission parameter may be inserted by the packet formatter 306. More specifically, when the group formatter 304 inserts the known data place holders, the packet formatter 306 may insert the known data instead of the known data place holders. Alternatively, when the group formatter 304 inserts the known data, the known data may be directly outputted without modification.

FIG. 20 illustrates a block diagram showing the structure of a packet formatter 306 being expanded so that the packet formatter 306 can insert the transmission parameter according to an embodiment of the present invention. More specifically, the structure of the packet formatter 306 further includes a known data generator 351 and a signaling multiplexer 352. Herein, the transmission parameter that is inputted to the signaling multiplexer 352 may include information on the length of a current burst, information indicating a starting point of a next burst, positions in which the groups within the burst exist and the lengths of the groups, information on the time from the current group and the next group within the burst, and information on known data.

The signaling multiplexer 352 selects one of the transmission parameter and the known data generated from the known data generator 351 and, then, outputs the selected data to the packet formatter 306. The packet formatter 306 inserts the known data or transmission parameter outputted from the signaling multiplexer 352 into the known data place holders outputted from the data interleaver 305. Then, the packet formatter 306 outputs the processed data. More specifically, the packet formatter 306 inserts a transmission parameter in at least a portion of the known data region instead of the known data, which is then outputted. For example, when a known data place holder is inserted at a beginning portion of region A within the data group, a transmission parameter may be inserted in a portion of the known data place holder instead of the actual known data.

Also, when the transmission parameter is inserted in the known data place holder instead of the known data, the transmission parameter may be block encoded in short periods and inserted. Alternatively, a pre-defined pattern may be inserted in accordance with the transmission parameter. More specifically, the signaling multiplexer 352 multiplexes the known data and the transmission parameter (or the pattern defined by the transmission parameter) so as to configure a new known data sequence. Then, the signaling multiplexer 352 outputs the newly configured known data sequence to the packet formatter 306. The packet formatter 306 deletes the main service data place holder and RS parity place holder from the output of the data interleaver 305, and creates a mobile service data packet of 188 bytes by using the mobile service data, MPEG header, and the output of the signaling multiplexer. Then, the packet formatter 306 outputs the newly created mobile service data packet to the packet multiplexer 240.

In this case, the region A of each data group has a different known data pattern. Therefore, the receiving system separates only the symbol in a pre-arranged section of the known data sequence and recognizes the separated symbol as the transmission parameter. Herein, depending upon the design of the transmitting system, the known data may be inserted in different blocks, such as the packet formatter 306, the group formatter 304, or the block processor 303. Therefore, a transmission parameter may be inserted instead of the known data in the block wherein the known data are to be inserted.

According to the second embodiment of the present invention, a transmission parameter including information on the processing method of the block processor 303 may be inserted in a portion of the known data region and then transmitted. In this case, a symbol processing method and position of the symbol for the actual transmission parameter symbol are already decided. Also, the position of the transmission parameter symbol should be positioned so as to be transmitted or received earlier than any other data symbols that are to be decoded. Accordingly, the receiving system may detect the transmission symbol before the data symbol decoding process, so as to use the detected transmission symbol for the decoding process.

Third Embodiment

Meanwhile, the transmission parameter may also be inserted in the field synchronization segment region and then transmitted. FIG. 21 illustrates a block diagram showing the synchronization multiplexer being expanded in order to allow the transmission parameter to be inserted in the field synchronization segment region. Herein, a signaling multiplexer 261 is further included in the synchronization multiplexer 260. The transmission parameter of the general VSB method is configured of 2 fields. More specifically, each field is configured of one field synchronization segment and 312 data segments. Herein, the first 4 symbols of a data segment correspond to the segment synchronization portion, and the first data segment of each field corresponds to the field synchronization portion.

One field synchronization signal is configured to have the length of one data segment. The data segment synchronization pattern exists in the first 4 symbols, which are then followed by pseudo random sequences PN 511, PN 63, PN 63, and PN 63. The next 24 symbols include information associated with the VSB mode. Additionally, the 24 symbols that include information associated with the VSB mode are followed by the remaining 104 symbols, which are reserved symbols. Herein, the last 12 symbols of a previous segment are copied and positioned as the last 12 symbols in the reserved region. In other words, only the 92 symbols in the field synchronization segment are the symbols that correspond to the actual reserved region.

Therefore, the signaling multiplexer 261 multiplexes the transmission parameter with an already-existing field synchronization segment symbol, so that the transmission parameter can be inserted in the reserved region of the field synchronization segment. Then, the signaling multiplexer 261 outputs the multiplexed transmission parameter to the synchronization multiplexer 260. The synchronization multiplexer 260 multiplexes the segment synchronization symbol, the data symbols, and the new field synchronization segment outputted from the signaling multiplexer 261, thereby configuring a new transmission frame. The transmission frame including the field synchronization segment, wherein the transmission parameter is inserted, is outputted to the transmission unit 270. At this point, the reserved region within the field synchronization segment for inserting the transmission parameter may correspond to a portion of or the entire 92 symbols of the reserved region. Herein, the transmission parameter being inserted in the reserved region may, for example, include information identifying the transmission parameter as the main service data, the mobile service data, or a different type of mobile service data.

If the information on the processing method of the block processor 303 is transmitted as a portion of the transmission parameter, and when the receiving system wishes to perform a decoding process corresponding to the block processor 303, the receiving system should be informed of such information on the block processing method in order to perform the decoding process. Therefore, the information on the processing method of the block processor 303 should already be known prior to the block decoding process. Accordingly, as described in the third embodiment of the present invention, when the transmission parameter having the information on the processing method of the block processor 303 (and/or the group formatter 304) is inserted in the reserved region of the field synchronization signal and then transmitted, the receiving system is capable of detecting the transmission parameter prior to performing the block decoding process on the received signal.

Receiving System

FIG. 22 is a block diagram illustrating a mobile service data receiving apparatus for processing mobile service data and electronic program information upon receiving mobile service data packet.

Referring to FIG. 22, the mobile service data receiving apparatus 900 according to an embodiment of the present invention includes a signal receiving unit 910, a demodulating unit 920, a demultiplexer 940, a data decoder 950, a PSI/PSIP database 960, an A/V decoder 970, an application controller (also called an application & UI manager) 980, a channel manager 982, a channel map 984, a flash memory 986, a user interface unit 988, a display 990, etc. In this case, according to an embodiment of the present invention, the data extractor 950 may be a PSI/PSIP decoder, so that the PSI/PSIP decoder will hereinafter be used instead of the data decoder for the convenience of description and better understanding of the present invention.

For example, the above-mentioned mobile service data receiving apparatus 900 may be a digital television (DTV) capable of receiving digital broadcast data, a mobile digital broadcast receiver, etc.

The signal receiving unit 910 receives a frequency of a specific channel, and outputs it.

The signal receiving unit 910 can receive mobile service data packet and main service data packet. In other words, the signal receiving unit 910 can selectively receive multiplexed main service data packet and multiplexed mobile service data packet. In this case, the aforementioned selective reception is as follows. For example, if it is assumed that the mobile service data packet and the main service data packet are multiplexed in a burst structure including a burst-on section and a burst-off section, and are then transmitted, the signal receiving unit 910 receives the mobile service data packet during the burst-on section. In this case, the burst-on section may include not only the mobile service data packet but also some parts of the main service data packet.

In other words, only the main service data packet may be transmitted during the burst-off section, and both the mobile service data packet and the main service data packet may be transmitted during the burst-on section. Thereafter, the signal receiving unit 910 divides the received data of the burst-on section into mobile service data packet and main service data packet.

In this case, the received broadcast signal includes a Program and System Information/Program and System Information Protocol (PSI/PSIP) table.

Specifically, the PSI/PSI table includes an Event Information Table (EIT) and a Virtual Channel Table (VCT).

In the meantime, the signal receiving unit 910 may be controlled by the channel manager 982.

The signal receiving unit 910 records the result of the received digital broadcast signal in the channel manager 982.

The demodulating unit 920 demodulates the reception (Rx) signal of the signal receiving unit 910, and divides the Rx signal into mobile service data packet and main service data packet. The demodulating unit 920 performs inverse processing of the transmission end's process which has been executed to improve a Rx performance of mobile service data. The signal processing of the demodulating unit 920 will be described later with reference to FIG. 23.

The demultiplexer 940 receives the demodulated signal from the demodulating unit 920, and performs demultiplexing on the received signal, so that it outputs main service data, PSI/PSIP table data associated with the main service data, mobile service data, and PSI/PSIP table data with the mobile service data. The mobile service data and associated PSI/PSIP table data will hereinafter be described using the mobile broadcast receiver as an example.

The demultiplexing of mobile audio data and mobile video data from among mobile service data may be controlled by the channel manager 982. The demultiplexing of the PSI/PSIP table may be controlled by the PSI/PSIP decoder 950.

The demultiplexed PSI/PSIP table is transmitted to the PSI/PSIP decoder 950. The demultiplexed mobile audio data and the demultiplexed video data are transmitted to the A/V decoder 970. The A/V decoder 970 includes an audio decoder and a video decoder. The audio decoder decodes the received audio data using an audio decoding algorithm, and the video decoder decodes the received video data using a video decoding algorithm.

The PSI/PSIP decoder 950 performs parsing the PSI/PSIP section constructing the table, and records electronic program information in the PSI/PSIP database 960. In this case, the PSI/PSIP decoder may be an example of the data decoder.

The channel manager 982 transmits a request for receiving a channel-associated information table by referring to the channel map 984, and receives a response to the request.

In this case, the PSI/PSIP decoder 950 controls the demultiplexing of the channel-associated information table, and transmits the A/V and data PID list to the channel manager 982.

The channel manager 982 directly controls the multiplexer 940 using the above transmitted A/V PID, so that it controls the A/V decoder 970.

The application controller 980 controls a Graphical User Interface (GUI) for displaying status information of the above receiving system on the OSD (On Screen Display).

Particularly, according to the present invention, the demultiplexer 940 demultiplexes the EIT, and transmits the demultiplexed result to the PSI/PSIP decoder 950.

The above-mentioned process for decoding the electronic program information from a table including program information can be readily understood, and a detailed description thereof will hereinafter be described with reference to FIG. 25. The table including the program information will hereinafter be described using the EIT as an example.

The PSI/PSIP decoder 950 detects the EIT and acquires information of mobile service data and program information of the inventive mobile service data.

For example, if the broadcast receiver 900 receives an EPG service request from a user, the channel manager 982 gains access to the PSI/PSIP decoder 950, and receives information associated with the request.

The application controller 980 controls the display 990, and transmits mobile service data and electronic program information associated with the mobile service data. For example, the electronic program information may be an Electronic Program Guide (EPG). In other words, the application controller 980 collects the electronic program information, and controls the EPG information applied to the display 990 using the collected electronic program information.

The user interface unit 988 receives a user's selection signal. For example, the user interface unit 988 may receive an EPG function call signal, or receive a signal for selecting a detailed function from among the EPG display.

The display unit 990 outputs not only mobile service data but also electronic program information associated with the mobile service data. In this case, the mobile service data and the electronic program information associated with the mobile service data may be displayed separately from each other, or may also be displayed at the same time.

FIG. 23 is a block diagram illustrating the demodulating unit of FIG. 22 according to the present invention.

Referring to FIG. 23, the demodulating unit recovers a carrier synchronization, a frame synchronization, and performs a channel equalization using known data, so that it improves a Rx performance. In this case, it should be noted that the known data has been inserted into the mobile service data section by the transmission system, and then the transmission system has transmitted the inserted result.

The demodulating unit 920 includes a demodulator 921, an equalizer 922, a known sequence detector 923, a block decoder 924, a data deformatter 925, a RS-frame decoder 926, a derandomizer 927, a data deinterleaver 928, a RS decoder 929, a data derandomizer 930, etc.

For the convenience of description, the data deformatter 925, the RS frame decoder 926, and the derandomizer 927 are hereinafter referred to as a mobile service data processor. The data deinterleaver 928, the RS decoder 929, and the data derandomizer 930 are hereinafter referred to as a main service data processor.

For example, provided that the reception system is a broadcast receiving system capable of outputting only mobile service data other than main service data, the demodulating unit 920 according to the present invention may include only the mobile service data processor (i.e., the data deformatter 925, the RS frame decoder 926, and the derandomizer 927) other than the main service data processor (i.e., the data deinterleaver 928, the RS decoder 929, and the data derandomizer 930).

And, provided that the reception system is a system capable of outputting both the main service data and the mobile service data, the demodulating unit 920 according to the present invention may include both the mobile service data processor (i.e., the data deformatter 925, the RS frame decoder 926, and the derandomizer 927) and the main service data processor (i.e., the data deinterleaver 928, the RS decoder 929, and the data derandomizer 930).

In this case, mobile service data and electronic program information associated with the mobile service data are simultaneously processed by the demodulating unit 920.

In more detail, the signal receiving unit 910 receives a frequency of a specific channel, converts the received frequency into an Intermediate Frequency (IF) signal, and outputs the converted result to the demodulator 921 and the known sequence detector 923.

The demodulator 921 receives the IF signal from the demodulator 921, performs an automatic gain control, a carrier recovery, and a timing recovery on the received IF signal to create a baseband signal, and outputs the baseband signal to the equalizer 922 and the known sequence detector 923.

The equalizer 922 compensates for channel distortion contained in the demodulated signal, and outputs the compensated result to the block decoder 924.

At this point, the known sequence detector 923 detects the known sequence place inserted by the transmitting end from the input/output data of the demodulator 921 (i.e., the data prior to the demodulation process or the data after the demodulation process). Thereafter, the place information along with the symbol sequence of the known data, which are generated from the detected place, is outputted to the demodulator 921 and the equalizer 922. Also, the known sequence detector 923 outputs a set of information to the block decoder 924. This set of information is used to allow the block decoder 924 of the receiving system to identify the mobile service data that are processed with additional encoding from the transmitting system and the main service data that are not processed with additional encoding. In addition, although the connection status is not shown in FIG. 23, the information detected from the known sequence detector 923 may be used throughout the entire receiving system and may also be used in the data deformatter 925 and the RS frame decoder 926. The demodulator 921 uses the known data symbol sequence during the timing and/or carrier recovery, thereby enhancing the demodulating performance. Similarly, the equalizer 922 uses the known data so as to enhance the equalizing performance. Moreover, the decoding result of the block decoder 924 may be fed-back to the equalizer 922, thereby enhancing the equalizing performance.

The equalizer 922 may perform channel equalization by using a plurality of methods. An example of estimating a channel impulse response (CIR) so as to perform channel equalization will be given in the description of the present invention. Most particularly, an example of estimating the CIR in accordance with each region within the data group, which is hierarchically divided and transmitted from the transmitting system, and applying each CIR differently will also be described herein. Furthermore, by using the known data, the place and contents of which is known in accordance with an agreement between the transmitting system and the receiving system, and the field synchronization data, so as to estimate the CIR, the present invention may be able to perform channel equalization with more stability.

Herein, the data group that is inputted for the equalization process is divided into regions A to C, as shown in FIG. 6A. More specifically, in the example of the present invention, each region A, B, and C are further divided into regions A1 to A5, regions B1 and B2, and regions C1 to C3, respectively. Referring to FIG. 6A, the CIR that is estimated from the field synchronization data in the data structure is referred to as CIR_FS. Alternatively, the CIRs that are estimated from each of the 5 known data sequences existing in region A are sequentially referred to as CIR_N0, CIR_N1, CIR_N2, CIR_N3, and CIR_N4.

As described above, the present invention uses the CIR estimated from the field synchronization data and the known data sequences in order to perform channel equalization on data within the data group. At this point, each of the estimated CIRs may be directly used in accordance with the characteristics of each region within the data group. Alternatively, a plurality of the estimated CIRs may also be either interpolated or extrapolated so as to create a new CIR, which is then used for the channel equalization process.

Herein, when a value F(A) of a function F(x) at a particular point A and a value F(B) of the function F(x) at another particular point B are known, interpolation refers to estimating a function value of a point within the section between points A and B. Linear interpolation corresponds to the simplest form among a wide range of interpolation operations. The linear interpolation described herein is merely exemplary among a wide range of possible interpolation methods. And, therefore, the present invention is not limited only to the examples set forth herein.

Alternatively, when a value F(A) of a function F(x) at a particular point A and a value F(B) of the function F(x) at another particular point B are known, extrapolation refers to estimating a function value of a point outside of the section between points A and B. Linear extrapolation is the simplest form among a wide range of extrapolation operations. Similarly, the linear extrapolation described herein is merely exemplary among a wide range of possible extrapolation methods. And, therefore, the present invention is not limited only to the examples set forth herein.

More specifically, in case of region C1, any one of the CIR_N4 estimated from a previous data group, the CIR_FS estimated from the current data group that is to be processed with channel equalization, and a new CIR generated by extrapolating the CIR_FS of the current data group and the CIR_N0 may be used to perform channel equalization. Alternatively, in case of region B1, a variety of methods may be applied as described in the case for region C1. For example, a new CIR created by linearly extrapolating the CIR_FS estimated from the current data group and the CIR_N0 may be used to perform channel equalization. Also, the CIR_FS estimated from the current data group may also be used to perform channel equalization. Finally, in case of region A1, a new CIR may be created by interpolating the CIR_FS estimated from the current data group and CIR_N0, which is then used to perform channel equalization. Furthermore, any one of the CIR_FS estimated from the current data group and CIR_N0 may be used to perform channel equalization.

In case of regions A2 to A5, CIR_N(i−1) estimated from the current data group and CIR_N(i) may be interpolated to create a new CIR and use the newly created CIR to perform channel equalization. Also, any one of the CIR_N(i−1) estimated from the current data group and the CIR_N(i) may be used to perform channel equalization. Alternatively, in case of regions B2, C2, and C3, CIR_N3 and CIR_N4 both estimated from the current data group may be extrapolated to create a new CIR, which is then used to perform the channel equalization process. Furthermore, the CIR_N4 estimated from the current data group may be used to perform the channel equalization process. Accordingly, an optimum performance may be obtained when performing channel equalization on the data inserted in the data group. The methods of obtaining the CIRs required for performing the channel equalization process in each region within the data group, as described above, are merely examples given to facilitate the understanding of the present invention. A wider range of methods may also be used herein. And, therefore, the present invention will not only be limited to the examples given in the description set forth herein.

Meanwhile, if the data being inputted to the block decoder 924 after being channel equalized from the equalizer 922 correspond to the mobile service data having additional encoding and trellis encoding performed thereon by the transmitting system, trellis decoding and additional decoding processes are performed on the inputted data as inverse processes of the transmitting system. Alternatively, if the data being inputted to the block decoder 924 correspond to the main service data having only trellis encoding performed thereon, and not the additional encoding, only the trellis decoding process is performed on the inputted data as the inverse process of the transmitting system.

The data group decoded by the block decoder 924 is inputted to the data deformatter 925, and the main service data are inputted to the data deinterleaver 928. According to another embodiment, the main data may also bypass the block decoder 924 so as to be directly inputted to the data deinterleaver 928. In this case, a trellis decoder for the main service data should be provided before the data deinterleaver 928. When the block decoder 924 outputs the data group to the data deformatter 925, the known data, trellis initialization data, and MPEG header, which are inserted in the data group, and the RS parity, which is added by the RS encoder/non-systematic RS encoder or non-systematic RS encoder of the transmitting system, are removed. Then, the processed data are outputted to the data deformatter 925. Herein, the removal of the data may be performed before the block decoding process, or may be performed during or after the block decoding process. If the transmitting system includes signaling information in the data group upon transmission, the signaling information is outputted to the data deformatter 925.

More specifically, if the inputted data correspond to the main service data, the block decoder 924 performs Viterbi decoding on the inputted data so as to output a hard decision value or to perform a hard-decision on a soft decision value, thereby outputting the result. Meanwhile, if the inputted data correspond to the mobile service data, the block decoder 924 outputs a hard decision value or a soft decision value with respect to the inputted mobile service data. In other words, if the inputted data correspond to the mobile service data, the block decoder 924 performs a decoding process on the data encoded by the block processor and trellis encoding module of the transmitting system.

At this point, the RS frame encoder of the pre-processor included in the transmitting system may be viewed as an external code. And, the block processor and the trellis encoder may be viewed as an internal code. In order to maximize the performance of the external code when decoding such concatenated codes, the decoder of the internal code should output a soft decision value. Therefore, the block decoder 924 may output a hard decision value on the mobile service data. However, when required, it may be more preferable for the block decoder 924 to output a soft decision value.

Meanwhile, the data deinterleaver 928, the RS decoder 929, and the derandomizer 930 are blocks required for receiving the main service data. Therefore, the above-mentioned blocks may not be required in the structure of a digital broadcast receiving system that only receives the mobile service data. The data deinterleaver 928 performs an inverse process of the data interleaver included in the transmitting system. In other words, the data deinterleaver 928 deinterleaves the main service data outputted from the block decoder 924 and outputs the deinterleaved main service data to the RS decoder 929. The RS decoder 929 performs a systematic RS decoding process on the deinterleaved data and outputs the processed data to the derandomizer 930. The derandomizer 930 receives the output of the RS decoder 929 and generates a pseudo random data byte identical to that of the randomizer included in the digital broadcast transmitting system. Thereafter, the derandomizer 930 performs a bitwise exclusive OR (XOR) operation on the generated pseudo random data byte, thereby inserting the MPEG synchronization bytes to the beginning of each packet so as to output the data in 188-byte main service data packet units.

Meanwhile, the data being outputted from the block decoder 924 to the data deformatter 925 are inputted in the form of a data group. At this point, the data deformatter 925 already knows the structure of the data that are to be inputted and is, therefore, capable of identifying the signaling information, which includes the system information, and the mobile service data from the data group. Thereafter, the data deformatter 925 outputs the identified signaling information to a block for processing signaling information (not shown) and outputs the identified mobile service data to the RS frame decoder 926. More specifically, the RS frame decoder 926 receives only the RS encoded and CRC encoded mobile service data that are transmitted from the data deformatter 925.

The RS frame encoder 926 performs an inverse process of the RS frame encoder included in the transmitting system so as to correct the error within the RS frame. Then, the RS frame decoder 926 adds the 1-byte MPEG synchronization service data packet, which had been removed during the RS frame encoding process, to the error-corrected mobile service data packet. Thereafter, the processed data packet is outputted to the derandomizer 927. The operation of the RS frame decoder 926 will be described in detail in a later process. The derandomizer 927 performs a derandomizing process, which corresponds to the inverse process of the randomizer included in the transmitting system, on the received mobile service data. Thereafter, the derandomized data are outputted, thereby obtaining the mobile service data transmitted from the transmitting system. Hereinafter, detailed operations of the RS frame decoder 926 will now be described.

FIG. 24 illustrates a series of exemplary step of an error correction decoding process of the RS frame decoder 926 according to the present invention. More specifically, the RS frame decoder 926 groups mobile service data bytes received from the data deformatter 925 so as to configure an RS frame. The mobile service data correspond to data RS encoded and CRC encoded from the transmitting system. FIG. 24( a) illustrates an example of configuring the RS frame. More specifically, the transmitting system divided the RS frame having the size of (N+2)*235 to 30*235 byte blocks. When it is assumed that each of the divided mobile service data byte blocks is inserted in each data group and then transmitted, the receiving system also groups the 30*235 mobile service data byte blocks respectively inserted in each data group, thereby configuring an RS frame having the size of (N+2)*235. For example, when it is assumed that an RS frame is divided into 18 30*235 byte blocks and transmitted from a burst section, the receiving system also groups the mobile service data bytes of 18 data groups within the corresponding burst section, so as to configure the RS frame. Furthermore, when it is assumed that N is equal to 538 (i.e., N=538), the RS frame decoder 926 may group the mobile service data bytes within the 18 data groups included in a burst so as to configure a RS frame having the size of 540*235 bytes.

Herein, when it is assumed that the block decoder 924 outputs a soft decision value for the decoding result, the RS frame decoder 926 may decide the ‘0’ and ‘1’ of the corresponding bit by using the codes of the soft decision value. 8 bits that are each decided as described above are grouped to create 1 data byte. If the above-described process is performed on all soft decision values of the 18 data groups included in a single burst, the RS frame having the size of 540*235 bytes may be configured. Additionally, the present invention uses the soft decision value not only to configure the RS frame but also to configure a reliability map. Herein, the reliability map indicates the reliability of the corresponding data byte, which is configured by grouping 8 bits, the 8 bits being decided by the codes of the soft decision value.

For example, when the absolute value of the soft decision value exceeds a pre-determined threshold value, the value of the corresponding bit, which is decided by the code of the corresponding soft decision value, is determined to be reliable. Conversely, when the absolute value of the soft decision value does not exceed the pre-determined threshold value, the value of the corresponding bit is determined to be unreliable. Thereafter, if even a single bit among the 8 bits, which are decided by the codes of the soft decision value and group to configure 1 data byte, is determined to be unreliable, the corresponding data byte is marked on the reliability map as an unreliable data byte.

Herein, determining the reliability of 1 data byte is only exemplary. More specifically, when a plurality of data bytes (e.g., at least 4 data bytes) are determined to be unreliable, the corresponding data bytes may also be marked as unreliable data bytes within the reliability map. Conversely, when all of the data bits within the 1 data byte are determined to be reliable (i.e., when the absolute value of the soft decision values of all 8 bits included in the 1 data byte exceed the predetermined threshold value), the corresponding data byte is marked to be a reliable data byte on the reliability map. Similarly, when a plurality of data bytes (e.g., at least 4 data bytes) are determined to be reliable, the corresponding data bytes may also be marked as reliable data bytes within the reliability map. The numbers proposed in the above-described example are merely exemplary and, therefore, do not limit the scope or spirit of the present invention.

The process of configuring the RS frame and the process of configuring the reliability map both using the soft decision value may be performed at the same time. Herein, the reliability information within the reliability map is in a one-to-one correspondence with each byte within the RS frame. For example, if a RS frame has the size of 540*235 bytes, the reliability map is also configured to have the size of 540*235 bytes. FIG. 24( a′) illustrates the process steps of configuring the reliability map according to the present invention. Meanwhile, if a RS frame is configured to have the size of (N+2)*235 bytes, the RS frame decoder 926 performs a CRC syndrome checking process on the corresponding RS frame, thereby verifying whether any error has occurred in each row. Subsequently, as shown in FIG. 24( b), a 2-byte checksum is removed to configure an RS frame having the size of N*235 bytes. Herein, the presence (or existence) of an error is indicated on an error flag corresponding to each row. Similarly, since the portion of the reliability map corresponding to the CRC checksum has hardly any applicability, this portion is removed so that only N*235 number of the reliability information bytes remain, as shown in FIG. 24( b′).

After performing the CRC syndrome checking process, the RS frame decoder 926 performs RS decoding in a column direction. Herein, a RS erasure correction process may be performed in accordance with the number of CRC error flags. More specifically, as shown in FIG. 24( c), the CRC error flag corresponding to each row within the RS frame is verified. Thereafter, the RS frame decoder 926 determines whether the number of rows having a CRC error occurring therein is equal to or smaller than the maximum number of errors on which the RS erasure correction may be performed, when performing the RS decoding process in a column direction. The maximum number of errors corresponds to a number of parity bytes inserted when performing the RS encoding process. In the embodiment of the present invention, it is assumed that 48 parity bytes have been added to each column.

If the number of rows having the CRC errors occurring therein is smaller than or equal to the maximum number of errors (i.e., 48 errors according to this embodiment) that can be corrected by the RS erasure decoding process, a (235,187)-RS erasure decoding process is performed in a column direction on the RS frame having 235 N-byte rows, as shown in FIG. 24( d). Thereafter, as shown in FIG. 24( f), the 48-byte parity data that have been added at the end of each column are removed. Conversely, however, if the number of rows having the CRC errors occurring therein is greater than the maximum number of errors (i.e., 48 errors) that can be corrected by the RS erasure decoding process, the RS erasure decoding process cannot be performed. In this case, the error may be corrected by performing a general RS decoding process. In addition, the reliability map, which has been created based upon the soft decision value along with the RS frame, may be used to further enhance the error correction ability (or performance) of the present invention.

More specifically, the RS frame decoder 926 compares the absolute value of the soft decision value of the block decoder 924 with the pre-determined threshold value, so as to determine the reliability of the bit value decided by the code of the corresponding soft decision value. Also, 8 bits, each being determined by the code of the soft decision value, are grouped to form 1 data byte. Accordingly, the reliability information on this 1 data byte is indicated on the reliability map. Therefore, as shown in FIG. 24( e), even though a particular row is determined to have an error occurring therein based upon a CRC syndrome checking process on the particular row, the present invention does not assume that all bytes included in the row have errors occurring therein. The present invention refers to the reliability information of the reliability map and sets only the bytes that have been determined to be unreliable as erroneous bytes. In other words, with disregard to whether or not a CRC error exists within the corresponding row, only the bytes that are determined to be unreliable based upon the reliability map are set as erasure points.

According to another method, when it is determined that CRC errors are included in the corresponding row, based upon the result of the CRC syndrome checking result, only the bytes that are determined by the reliability map to be unreliable are set as errors. More specifically, only the bytes corresponding to the row that is determined to have errors included therein and being determined to be unreliable based upon the reliability information, are set as the erasure points. Thereafter, if the number of error points for each column is smaller than or equal to the maximum number of errors (i.e., 48 errors) that can be corrected by the RS erasure decoding process, an RS erasure decoding process is performed on the corresponding column. Conversely, if the number of error points for each column is greater than the maximum number of errors (i.e., 48 errors) that can be corrected by the RS erasure decoding process, a general decoding process is performed on the corresponding column.

More specifically, if the number of rows having CRC errors included therein is greater than the maximum number of errors (i.e., 48 errors) that can be corrected by the RS erasure decoding process, either an RS erasure decoding process or a general RS decoding process is performed on a column that is decided based upon the reliability information of the reliability map, in accordance with the number of erasure points within the corresponding column. For example, it is assumed that the number of rows having CRC errors included therein within the RS frame is greater than 48. And, it is also assumed that the number of erasure points decided based upon the reliability information of the reliability map is indicated as 40 erasure points in the first column and as 50 erasure points in the second column. In this case, a (235,187)-RS erasure decoding process is performed on the first column. Alternatively, a (235,187)-RS decoding process is performed on the second column. When error correction decoding is performed on all column directions within the RS frame by using the above-described process, the 48-byte parity data which were added at the end of each column are removed, as shown in FIG. 24( f).

As described above, even though the total number of CRC errors corresponding to each row within the RS frame is greater than the maximum number of errors that can be corrected by the RS erasure decoding process, when the number of bytes determined to have a low reliability level, based upon the reliability information on the reliability map within a particular column, while performing error correction decoding on the particular column. Herein, the difference between the general RS decoding process and the RS erasure decoding process is the number of errors that can be corrected. More specifically, when performing the general RS decoding process, the number of errors corresponding to half of the number of parity bytes (i.e., (number of parity bytes)/2) that are inserted during the RS encoding process may be error corrected (e.g., 24 errors may be corrected). Alternatively, when performing the RS erasure decoding process, the number of errors corresponding to the number of parity bytes that are inserted during the RS encoding process may be error corrected (e.g., 48 errors may be corrected).

After performing the error correction decoding process, as described above, a RS frame configured of 187 N-byte rows (or packets) maybe obtained, as shown in FIG. 24( f). Furthermore, the RS frame having the size of N*187 bytes is sequentially outputted in N number of 187-byte units. Herein, as shown in FIG. 24( g), the 1-byte MPEG synchronization byte that was removed by the transmitting system is added at the end of each 187-byte packet, thereby outputting 188-byte mobile service data packets.

Embodiments illustrating application examples of the mobile service data packet processed/generated from the above-mentioned reception system will hereinafter be described. The present invention will disclose a method for extracting electronic program information from the PSI/PSIP information associated with the mobile service data formed by the demultiplexed mobile service packet, and employing the extracted information.

FIG. 25 is a structural diagram illustrating a bit stream syntax associated with an Event Information Table (EIT) section including electronic program information according to the present invention. At least one EIT section forms a single EIT.

A method for defining electronic program information associated with mobile service data using the EIT section will hereinafter be described with reference to FIG. 25. The EIT provides detailed information of an event contained in a virtual channel. The virtual channel is identified by a source identification field, and each event is identified by a unique identifier, such that the EIT provides the above-mentioned detailed information.

The Event Information Table (EIT) is one of tables of the PSIP including a title, start time, and duration of at least one event of the virtual channel. As can be seen from FIG. 25, the EIT section includes a plurality of fields.

The “table_id” field is composed of 8 bits, and has the value of “0xCB”, such that a corresponding section belongs to the EIT.

The “section_syntax_indicator” field includes a single bit, and is set to the value of “1”.

The “private_indicator” field is composed of a single bit (i.e., a 1-bit field), and is set to the value of “1”.

The “source_id” field is an identifier for identifying a virtual channel carrying an event generated in a corresponding section.

The “version_number” field is an EIT entity version. In an embodiment of the present invention, event change information contained in an EIT which has a new version number in association with a conventional version number is recognized as the latest change information.

The “current_next_indicator” field indicates whether event information contained in a corresponding EIT is current information or future information.

The “num_event” field indicates the number of events contained in a channel having the above-mentioned source ID. Namely, an event loop is located under the “num_event” field, and the event loop is repeated several times corresponding to the number of events.

The above-mentioned EIT section field is commonly applied to at least one event contained in a single EIT section.

The “for(j=0;j<num_events_in_section;j++){ }” loop describes characteristics of individual events. The following fields are fields indicating detailed information of individual events. Therefore, the following fields are individually applied to corresponding events described in the EIT section.

The “event_id” field contained in the event loop identifies individual events. Event ID's numerals are considered to be some parts of an event “ETM_ID” (identifier for event Extended Text Message).

The “start_time” field indicates a start time of an event. Therefore, program's start time information provided from electronic program information is collected from the “start_time” field.

The “length_in_seconds” field indicates a duration time of an event. Therefore, program's end time information provided from electronic program information is collected from “length_in_seconds” field. Namely, a value of the “start_time” field and a value of the “length_in_seconds” field are summed up, such that the end time information can be collected.

The “title_text( )” field may be used to indicate a title of a broadcast program.

FIG. 26A is a structural diagram illustrating a syntax structure associated with a table indicating current time information according to the present invention. The present invention can use all kinds of tables indicating current time information. However, for the convenience of description, the present invention will use only a System Time Table (STT) as an example of the current time information table. The current time information is some parts of electronic program information, and is received as mobile service data packet according to the above-mentioned transmission/reception (Tx/Rx) scheme.

The current time information receives/detects a table including current time information such as a System Time Table (STT). And, the current time may be entered by a user. In other words, a user may enter the current time on the OSD, or the reception system detects the current time from the table including the current time information, and establishes the detected current time.

In this case, there may be a difference between an absolute time (e.g., Universal Time Coordinated (UTC) or Greenwich Sidereal Time (GST)) and a regional time. In this case, this difference may be corrected by a local time. This regional type may be set in a broadcast receiver by a user.

In the case of the mobile broadcast receiver, a region may be frequently changed to another region. In this case, the user must newly establish a region whenever a current region is changed to another region, resulting in greater inconvenience of use. Therefore, the present invention includes region information (or local time) in a table indicating electronic program information, and transmits the resultant table.

In this case, although the region information may be inserted into any table including any table including the electronic program information, it is assumed that the region information contained in the STT is transmitted to the receiver, and the receiver receives this information and establishes the local time. In this case, the absolute time information and the region information may be transmitted on a single table (See FIGS. 26A and 26B), and may also be transmitted using an additional table (See FIG. 27) including only region information.

In FIG. 26A, the “table_id” field in the STT section is composed of 8 bits, and has the value of “OxCD”. In this case, the receiver determines that a corresponding section belongs to a System Time Table (STT).

The “section_syntax_indicator” field includes a single bit, and is set to the value of “1”.

The “private_indicator” field is composed of a single bit (i.e., a 1-bit field), and is set to the value of “1”.

The “current_next_indicator” field indicates whether time information contained in a corresponding sTT section is current information or future information.

The “system_time” field is composed of 32 bits, and indicates a current time in units of seconds from a Universal Time Coordinated (UTC) of a reference time.

The “GPS_UTC_offset” field is composed of 8 bits, and indicates a value for correcting a difference between the GPS time and the UTC time.

The “Daylight_saving” field is composed of 16 bits, and determines whether a daylight-saving time control is applied or not. And, the “Daylight_saving” field indicates a date and time at which the daylight-saving time is applied.

The offset information from among the inventive regional information may be contained in a reserved filed of the STT, or may be added as a new descriptor to the reserved descriptor.

FIG. 26B is a structural diagram illustrating a local time offset descriptor syntax according to the present invention.

Referring to FIG. 26B, the local time offset descriptor corrects an offset related to the absolute time, and indicates region information for establishing a local time for each reception (Rx) region.

The local time offset descriptor includes the “descriptor_tag” field and the “descriptor_length” field. The “descriptor_tag” field identifies a descriptor in the STT, and the “descriptor_length” field indicates the length of a local time descriptor.

The “for(i=0, i<N; i++){ }” loop indicates detailed region information.

The “country_code” field is composed of 24 bits, and identifies individual countries for receiving broadcast data according to individual country code values.

The “country_region_id” field is composed of 6 bits, and different times may be applied to individual regions of a single country, so that the “country_region_id” field identifies a broadcast Rx region according to a country region ID field value.

The reserved field is composed of a single bit (i.e., 1 bit), and has no function for future use. In other words, if a specific value for identifying a time must be added in the future, a corresponding value may be inserted into this reserved field.

The “local_time_offset” field is composed of 40 bits, and determines a time offset value from the UTC using the received country code and the received country region ID value.

The “local_time_offset_polarity” field is composed of a single bit (1 bit), and determines a sign of the local time offset. In other words, the “local_time_offset_polarity” field indicates whether the offset correction is positive(+) or negative(−) on the basis of the UTC.

The “time_of_change” field is composed of 4 bits, and indicates a date and time of the time change using the MJT and the UTC.

The “next_time_offset” field is composed of 16 bits. If the time change from the UTC occurs, the “next_time_offset” field indicates the next offset time.

In this case, the local time offset descriptor may include the above-mentioned all fields, or may also include only a minimum number of values required for correcting the local time. For example, if the local time offset descriptor includes a country code field and a country region ID field, and is then transmitted to the receiver, the receiver can correct the local time offset on the condition that it has recognized a offset correction value of a region code.

And, if the local time offset descriptor does not transmit the country code field and the country region ID field, includes the local time offset field and the local time offset polarity field and the resultant the local time offset descriptor is transmitted to the receiver, the receiver can correct the local time using an offset value although it does not know detailed region information.

FIG. 27 is a structural diagram illustrating a syntax associated with a Local Time Table (LTT) section according to the present invention. In other words, region information including a local time may be contained as a descriptor type in the STT as shown in FIG. 26B, or may be transmitted to an additional table (e.g., LTT).

Referring to FIG. 27, the LTT section syntax selectively includes the “country code” field, the “country_region_id” field, the “local_time_offset” field, and the “local_time_offset polarity” field of FIG. 26. If necessary, the LTT section syntax may further include the reserved field.

The fields of FIG. 27 are the same as those of FIGS. 25 and 26.

According to a method for detecting the PSIP information and displaying current time information on the EPG, the present invention may combine standard time information and region information set in the broadcast receiver set, and may display the current time information on the EPG according to the combined result. Otherwise, the present invention receives the standard time information and the local time information at the same time, and automatically combines/establishes a current time according to a local time of a Rx region.

The receiver outputs the information collected from the table including the above-mentioned program information to various EPG ways. A variety of EPG display formats will hereinafter be described with reference to the annexed drawings. For the convenience of description and better understanding of the present invention, the mobile service data is referred to as a program.

FIG. 28 shows a display format of an Electronic Program Guide (EPG) according to the present invention.

Referring to FIG. 28, the EPG shows mobile service data broadcast from a virtual channel, i.e., time-flow information of an event. Information displayed on the EOG is extracted from the table including the electronic program information.

For example, FIG. 28 is a program schedule guide from 17:00 o'clock to 04:00 o'clock of broadcast programs of four virtual channels (i.e., minor channel Nos. “1”, “2”, “3”, and “100”) in a physical channel (i.e., a major channel No. 51).

The above-mentioned program schedule guide may also be called an electronic program guide (EPG).

“1-A”, “1-B”, . . . , “1-E” indicate titles of programs to be broadcasted from the “51-1” channel.

“2-A”, . . . , “3-D” indicate titles of programs of corresponding virtual channels.

Referring to an upper left part of FIG. 28, a circle-end arrow indicates a current time. As described above, the current time is collected and controlled.

Referring to an upper part of FIG. 28, a sharp-end arrow indicates a time zone of an event contained in a single EIT-k from among EIT-k (k=0˜127).

For example, 8 absolute times are contained in 24 hours of a day, i.e., “0:00” o'clock, “3:00” o'clock, “6:00” o'clock, “9:00” o'clock, “12:00” o'clock, “15:00” o'clock, “18:00” o'clock, and “21:00” o'clock.

If a current time “17:19” o'clock is used as a reference time, a broadcast channel is “51-1” and “51-2”.

The above-mentioned channels are considered to be active virtual channels. If a current time reaches 1:00 o'clock AM, there is no broadcast program, so that the “51-1” channel is changed to an inactive channel.

The “51-3” channel may be considered to be an inactive channel over which the “3-A” broadcast program will be broadcast from 19:00 o'clock.

In the meantime, empty spaces among the “3-A”, “3-B”, “3-C”, and “3-D” broadcast programs indicate advertisement broadcast program and others.

The “51-100” channel shows a data broadcast dedicated channel having no A/V data. The mobile service data includes A/V data and other service data, so that the A/V data and other information may be simultaneously displayed on the EPG.

The aforementioned data on EPG is an event contained in the EIT of the PSIP, and may include a variety of information (e.g., event title data, event start time data, event duration data, caption data, and rating data)

As described above, the EPG includes a first zone on a horizontal axis and a second zone on a vertical axis. One of the horizontal and vertical axes includes channel information, and the other one includes time information. Program information is located at a crossing point between the channel-information axis and the time-information axis.

The EPG may be displayed in various ways. For example, the EPG may be displayed in grid type, 8-days type, now-and-next type, and single type methods. The above-mentioned display format modes may be changed as necessary.

A predetermined transparency can be applied to an output mode of all windows contained in a program guide. In other words, if a program guide is displayed while a user views a program, and the program guide is displayed on the display screen of the viewing program, the program guide is displayed on a semitransparent window, so that the user can view a background screen. In this case, the window's transparency may be adjusted by the user.

FIG. 29 shows an output format of an Electronic Program Guide (EPG) according to an embodiment of the present invention.

Referring to FIG. 29, the EPG has a two-dimensional structure composed of a horizontal axis and a vertical axis. One of the horizontal and vertical axes includes channel information, and the other one of the vertical axes includes time information. In this case, the channel information may be located on the vertical axis, and the time information may be located on the horizontal axis, and vice versa. And, a title of a program which is received at a corresponding time of a corresponding channel is displayed at a crossing point between the horizontal axis and the vertical axis.

In other words, several electronic program information units are received and stored in the memory. In association with several channels, program schedule information of individual time zones is configured in the form of a list, and is then transmitted to the display. The above-mentioned description will be called a grid-type EPG.

The length of a cell at which the program title is located is proportional to the time. In other words, the program's start time information and the program's end time information are collected, the collected information is controlled to be displayed according to time information on a time axis. According to the above-mentioned embodiment, the length of each cell at which the program title is located is changed according to individual programs. In the meantime, due to a short duration of the program, the length of cell may be insufficient to display the program title. In this case, the program title may be denoted by reducing a font size, only some parts of the program title may be denoted using an ellipsis ( . . . ), or scroll or direction keys are provided on the EPG, so that blind text data can be displayed on the EPG. And, a text sliding function may also be provided to the above-mentioned grid-type EPG.

Next, embodiments of functions for use in the grid-type EPG will hereinafter be described. The following applicable functions irrespective of EPG-type embodiments can also be applied to EPG formats of other output types.

An input-type indication cell indicates that a current-selected input signal is one of various input types, for example, a TV signal, an audio signal, a data signal, or a software update signal.

A channel list cell indicates at least one of a channel name, a channel name, and a channel logo, so that it indicates information of a channel on which a program title is loaded. The number of channels is at least one. In this case, 7 channels can be simultaneously OSD-displayed on a single display window. If the number of Rx channels is at least “7”, the grid-type EPG may view the next channel information using either the scroll function or the page shift function.

The date cell indicates a date at which the program is received. In this case, the EPG may be composed of several dates. In this embodiment, the EPG may display program information of 8 days.

The program title cell displays titles of programs, which have been received during a predetermined time in association with a predetermined channel. For example, the program title cell may display program title information.

The time list provides reference time information indicating a program reception time. For example, the time list may be configured in units of seconds, minutes, or hours. The EPG displayed on a single screen (i.e., a single OSD) may display program information during a predetermined time.

The current time cell indicates a current time, and indicates current date- and time-information.

The current time indicator is an indicator for indicating a current time on the time list. A program of a cell located at a time zone indicated by the current time indicator can be currently displayed. Either a reserved viewing or a reserved recording of a program of a cell located at a time list zone after the current time indicator can be made available. In this case, prior to a time reserved for the viewing or the recording, the current time indicator may inform the user of a function setup method using the OSD, and may query the user whether to execute the function using the OSD.

A function key for receiving a signal from a user who selects a function capable of being provided will hereinafter be described. For the convenience of description, the function key will hereinafter be referred to as a user interface unit. If the user's selection signal is entered by the function key, a controller controls this entry user's selection signal.

The user can select a variety of input types using an input-type selection menu, for example, a TV broadcast signal, an audio broadcast signal, a data broadcast signal, and a software upgrade signal. In this case, the TV broadcast signal may be displayed to identify a satellite signal, a cable signal, and a terrestrial broadcast signal, respectively. Otherwise, the TV broadcast signal may be displayed as only a TV broadcast signal irrespective of broadcast types. In other words, if the user selects a TV broadcast signal as an input type, the EPG outputs program information received as the TV broadcast signal. If the user selects a data broadcast signal as an input type, the EPG outputs program information received as the data broadcast signal.

The mode selection menu allows the user to freely select a desired one from among a plurality of embodiment modes based on various EPG output formats. In other words, by the mode selection menu, the EPG display mode is changed among grid type, 8-days type, now-and-next type, and single type methods. For example, if the user selects the single-type EPG using the mode-selection menu while the EPG is being displayed in the grid type, the EPG is displayed in the single type.

Also, a program title and a visual indicator are simultaneously displayed on either the EPG display window or a program title cell, so that the visual indicator may inform the user whether a predetermined functions is established or not.

The visual indicator for indicating the above-mentioned established function or program characteristics can be implemented in the form of all kinds of formats. The visual indicator must be distinguished from other indicators in order to be easily recognized by the user. Namely, provided that several indicators can be distinguished in color whereas they have the same shape, they may be used as different function setup indicators and may also be implemented in other shapes as necessary.

In this case, a variety of function setup indicators can be displayed according to this embodiment, for example, a reserved-viewing indicator (See “Reminder icon” in drawings), a reserved-recording indicator (See “Record icon” in drawings), and a recording-status indicator.

A variety of indicators can be displayed to indicate a program character or program characteristics, for example, a pay-per-view (PPV) indicator, a series-program indicator, and a program-viewable age, and a preferred-channel indicator. The above-mentioned indicators have been disclosed for only illustrative purposes, are designed to indicate program's characteristics, and are displayed as visual icons on the EPG.

An input-type icon for visually indicating the input type can be used, and a channel logo for visually identifying channels of a channel list can be displayed.

The above-mentioned description may also be applied to the following other EPG display formats.

FIG. 30 shows an output format of an Electronic Program Guide (EPG) according to another embodiment of the present invention.

Referring to FIG. 30, the EPG provides program information for 1 day, and also provides much more program information for several days. In this case, if the user sequentially moves the time list of FIG. 2, he or she can view all of the program information of the several days. However, the user must directly scroll the time list until a time zone of a desired date is displayed.

Therefore, in order to effectively control the above-mentioned operation, the EPG can be displayed in the 8-days type (hereinafter referred to as “8-days type EPG”). Namely, when the receiver receives program information, stores the received program information, configures the stored program information in the form of an EPG, displays it on the screen, program information of several days may be configured in the form of a single EPG. According to this embodiment, it is assumed that program information of 8 days is displayed. However, it should be noted that 8 days have been disclosed for only illustrative purposes, and one or more days can also be used in this embodiment. For the convenience of description and better understanding of the present invention, it is assumed that the several days are set to 8 days.

The 8-days type enables a user to select channel information, time information, program title information, and several days provided from the EPG. Namely, a date tap for 8 days is displayed on the grid-type EPG. So, if the user selects a desired date, a time zone moves to program information of the selected date.

The above-mentioned date tap enables the user to identify several days provided from the EPG, so that the user can select a desired day using the date tap. It should be noted that there is no limitation in identification contents of the date tap. For example, the date tap can be identified in different ways, for example, “Today 10 Apr”, “Wed 11 Apr”, “Thur 12 Apr”, “Fri 13 Apr”, “Sat 14 Apr”, “Sun 15 Apr”, “Mon 16 Apr”, “Tues 17 Apr”, as shown in FIG. 30.

In this case, if user-desired program information is tomorrow's program information, the user needs to select the date tap of “Wed 11 Apr”. For another example, the above-mentioned date tap may be implemented in “today”, “tomorrow”, or “the day after tomorrow” format or other formats “1, 2, 3 . . . ”, instead of directly indicating the date. In this way, the date tap can be implemented with all kinds of user-distinguishable types.

A method for implementing the EPG display format is as follows. A broadcast receiver receives electronic program information, stores the received electronic program information, and displays program information, channel information, and time information on the screen. If a user moves a cursor, and selects a current-date-zone tap and other-date-zone tap, program information of the selected date zone is displayed.

FIG. 31 shows another output format of an Electronic Program Guide (EPG) according to another embodiment of the present invention.

In more detail, FIG. 31 shows an EPG display format which enables a user to easily select a time zone of a desired date, in a similar way to the above-mentioned EPG display format of FIG. 30.

Referring to FIG. 31, the date cell of FIG. 29 includes at least one of a scroll key, right and left keys, and up and down keys. In this case, the user may move a cursor using the scroll key, so that the date area may be shifted.

In a method for implementing the EPG display format, the broadcast receiver receives electronic program information, stores the received electronic program information, and displays program information, channel information, and time information on the screen. If the user moves a cursor to another location so that the date zone is changed, the broadcast receiver outputs program information of the changed date zone.

FIG. 32 shows another output format of an Electronic Program Guide (EPG) according to another embodiment of the present invention.

Referring to FIG. 32, channel information and time information are configured in the form of a two-dimensional shape. A broadcast receiver displays program information on the EPG. In FIG. 32, a time axis of the EPG displays a current-receiving program (NOW) and a next-receiving program (NEXT). Therefore, for the convenience of description, this EPG display format is referred to as a “now-and-next type”.

The now-and-next type displays title information of programs contained in the current- and next-time zones. The length of a cell indicating the program title is not proportional to the time. In brief, in the case of the now-and-next type, the EPG is displayed in only NOW and NEXT zones, irrespective of a program's duration time.

The above-mentioned EPG display format will hereinafter be described in detail. The broadcast receiver receives electronic program information, stores the received electronic program information, and displays the electronic program information along with channel information and time information on the screen. In this case, the time information does not indicate detailed time information, and indicates the presence or absence of the next program of a current-receiving program.

FIG. 33 shows another output format of an Electronic Program Guide (EPG) according to another embodiment of the present invention.

Referring to FIG. 33, channel information and time information are configured in the form of a two-dimensional shape. The EPG displays program information, and displays information of only one channel. Namely, differently from the grid-type EPG for displaying program information of several channels, the EPG of FIG. 33 displays information of only one channel. For the convenience of description, this EPG of FIG. 33 is called a single-type EPG.

A channel map for enabling a user to select several channels is displayed. If the user selects a single channel, the EPG displays only 1-channel program information from among an overall time zone, the user moves a cursor to No. 7 channel, only No. 7 channel's program information from among a total time zone is displayed.

In this case, if the user moves a cursor on the grid-type EPG display format of FIG. 29, and selects a specific program title, the single-type EPG may be displayed in a channel including the selected program.

In a method for implementing the above-mentioned single-type EPG of FIG. 33, the broadcast receiver receives electronic program information, stores the received electronic program information, displays the program information along with channel information and program title information on the screen. In this case, if the user selects one of the displayed program titles using the cursor, a single-channel format EPG, which includes the row or column of a sequential program list including the selected title, is displayed.

In this case, the horizontal axis and the vertical axis of a 2-dimensional (2D) shape may be a time area and a channel area, respectively. In this case, the horizontal axis or the vertical axis may be changed according to a screen ratio. For example, in the case of a broadcast receiver equipped with a display on which a vertical length is longer than horizontal axis, the vertical axis may be set to the channel area, and the horizontal axis may be set to the time area. In this embodiment, data of a display including a larger-sized time area may be displayed on a single screen.

The above-mentioned embodiment has been disclosed for only illustrative purposes, the opposite embodiments can also be made available. Namely, in the above-mentioned embodiment, a single channel area becomes longer, detailed program title information of a program assigned to a predetermined time area may be displayed on a single screen.

If a pivot function is executed in the above-mentioned 2D structure, the row and column are changeable as shown in FIGS. 34A and 34B, so that the horizontal and vertical areas can be configured.

FIGS. 34A and 34B show two-dimensional pivot functions according to an embodiment of the present invention.

Referring to 34A, the horizontal axis is set to a single channel area, and the vertical axis is set to a time area, so that program information of a long time area is displayed on a single screen. In this case, if title information of the program becomes longer, the long title information is not displayed on the screen, and the user must scroll the screen using a scroll- or direction-key.

In this case, during the display time of a short time area, the user may desire to output program title information on a single screen. In this case, the pivot function may be executed, so that the vertical- and horizontal-configurations are rotated on the basis of a predetermined axis, so that the horizontal and vertical screen configurations are changed. Namely, referring to FIG. 34A, a first side and a second side may be a channel area and a time area, respectively. The channel area and the time area are rotated on the basis of a predetermined axis, and the first and second sides are differently configured, such that the EPG screen display can be controlled. In this case, if the pivot function of the first and second sides is executed, the first-side's area and the second-side's area are maintained but the ratio of the first side to the second side may be changed to another ratio. And, another embodiment in which not only the length ratio but also the first=and second-sides' areas area are changed, can also be made available.

Referring to FIG. 34B, the first-side's screen configuration and the second-side's screen configuration on the EPG display format of FIG. 34A are changed to others, such that that the first-side's area configuration and the second-side's area configuration are changed to other configurations.

The first side of FIG. 34A has been assigned to a channel area, and the second side of FIG. 34A has been assigned to a time area, such that program information has been displayed. In FIG. 34B, the second side is assigned to a channel area, and the first side is assigned to the time area, so that program title information of a longer area is displayed on a single screen.

A method for implementing the EPG information which can be displayed in a variety of formats will hereinafter be described.

Referring to FIG. 35, the method for controlling EPG information includes a first step, and a second step, and a third step. At the first step, electronic program information of mobile service data is received and displayed. At the second step, a predetermined program is selected from the electronic program information. At the third step, mobile service data corresponding to the selected program is received and displayed.

Detailed descriptions of the embodiment of FIG. 35 will hereinafter be described.

FIG. 35 is a flow chart illustrating the EPG implementation method according to the present invention. The first step is as follows. If a user enters the EPG output selection signal at step S352 on the condition that either the first program is displayed at step S351 or mobile service data has no signal input, the EPG is displayed at step S353. In this case, the first program and the EPG may be displayed at the same time. Otherwise, the first program stops operation and only the EPG may be displayed.

If a predetermined title may not be selected on the displayed EPG at step S354, the EPG-off signal may be entered, or a predetermined time elapses at step S355, the EPG display is switched off at step S356.

If a predetermined title is selected on the displayed EPG at step S354, the selected program is set to the first program at step S357. Namely, the selected program is set to a program to be received and displayed.

Thereafter, the EPG display is switched off, the new program is displayed as a first program.

FIGS. 36A˜36C show EPG implementation examples according to an embodiment of the present invention.

Referring to FIGS. 36A to 36C, EPG data is displayed, and at the same time a preview image is displayed.

If a cursor moves a cursor to a program title cell on the EPG image, the EPG data is displayed and at the same time a corresponding program is received and displayed. In this case, the preview image may be displayed only when the user selects a program title cell on the EPG image. If a cursor moves a cursor to another location using direction keys, the preview image may be displayed although the program title cell is not selected by the user. Namely, while the user searches for a program guise on the EPG, currently-searching programs may be displayed on the preview image.

The preview image and the EPG data may be simultaneously displayed on the EPG output screen area and an additional area, or may also be displayed at the same area as the EPG output image. And, the preview image and the EPG data can be simultaneously displayed at a full screen ratio or portion screen ratio on the same area as the EPG output screen.

FIG. 36A shows a preview image displayed at an area spaced apart from the EPG output screen area. FIG. 36B shows a preview image displayed at the same area as the EPG output screen area. In this case, the preview image may be displayed at a full screen ratio, or may also be displayed at a portion screen ratio.

FIG. 36C shows that the preview image is displayed on the EPG output screen area and the additional area, and at the same time a mobile data screen of a background screen (or back screen) is displayed.

In FIGS. 36A˜36C, a first program is an original viewing program, and a second program is a preview program.

FIG. 37 shows implementation examples of EPG preview functions of FIGS. 36A˜36C.

A method for controlling EPG information will hereinafter be described with reference to FIG. 37. At a first step, the method for controlling the EPG information receives electronic program information of mobile service data, and outputs a program guide. At a second step, the EPG-information control method receives a selection signal of the program title on the program guide. At a third step, the EPG-information control method simultaneously outputs the selected program and the program guide.

During the above-mentioned first step, the electronic program information of the mobile service data is received and displayed.

If a user enters the EPG output selection signal at step S372 on the condition that either the first program is displayed at step S371 or mobile service data has no signal input, the EPG is displayed at step S373. In this case, the first program and the EPG may be displayed at the same time. Otherwise, the first program stops operation and only the EPG may be displayed.

At the above second step, a predetermined program title is selected by the user on the program guide at step S374. In this case, the selection signal can be entered in various ways. For example, if a cursor moves to a program title cell on the EPG, and a corresponding program title cell is highlighted, this condition may be considered that the selection signal has been entered. If a function selection key of a predetermined program title has been entered, this condition may be considered that the selection signal has been entered. The function selection of the predetermined program title is displayed on an option window, and a current-implementable function can be selected on the option window.

At the above third step, the selected program and the program guide are simultaneously displayed. The selected program is displayed on the preview image at step S375. At this step S375, video or audio information of a program is displayed. In this case, video information may be a moving image or a still image, or both of them. And, the still image may also be displayed in the form of a slideshow. During a predetermined time, a still image or slideshow-based still images are displayed. During a predetermined time after the program selection, a still image or slideshow-based still image are displayed. Then, after the predetermined time has elapsed, moving images may also be displayed as necessary. Output formats of the preview image have been described in FIGS. 36A to 36C.

If an output selection signal for a main image of a corresponding program is selected in the preview output images of the selected program at step S375, the selected program is set to a first program at step S376. Namely, the selected program is determined to be a program which will be received and displayed.

Thereafter, the EPG output is switched off, and the above setup new program is displayed on a first program.

After the preview image has been displayed, the EPG output signal is entered on the condition that a predetermined program title has not been selected at step S376. If the EPG output off signal is entered or a predetermined time elapses at step S379, the EPG output is switched off at step S380.

FIG. 38 is a flow chart illustrating a method for implementing an EPG preview function of FIGS. 36A˜36C according to another embodiment of the present invention.

Referring to FIG. 38, a method for controlling EPG information includes: a) displaying mobile service data at a viewing mode; b) receiving electronic program information of mobile service data, and displaying a program guide; c) storing channel information of mobile service data at a viewing mode; d) receiving a selection signal of a program title on the program guide; and e) simultaneously outputting the selected program and the program guide. In this case, if the program title for the main screen output function is selected on the program guide, the selected program is displayed. In this case, if a current mode returns to the viewing mode without selecting the main screen output function, the receiver receives data of a channel of an original viewing mode, and outputs the received data.

Detailed descriptions of the above-mentioned steps will hereinafter be described.

At a viewing mode, mobile service data is displayed at step S381. This program is called a first program. The above step (b) for receiving/displaying electronic program information of mobile service data is as follows. If an EPG output selection signal is entered at step S372 during the output time of the first program at step S381, channel information of the first program is stored at step S383, and then EPG data is displayed at sep S384.

The above step for receiving the program title's selection signal from the program guide is as follows. A predetermined program title is selected by a user on the program guide at step S385. In this case, the selection signal may be entered in various ways. For example, if a cursor moves to the program title cell on the EPG such that a corresponding cell is highlighted, this condition may be considered that a selection signal has been entered or a function selection key of a predetermined program title has been entered. And, if a program title cell is highlighted on a touchscreen, this condition may be considered that the selection signal has been entered. The function selection of the predetermined program title is displayed on an option window, and a current-implementation function may be selected on the option window.

At the above step for simultaneously displaying the selected program and the program guide is as follows. EPG is displayed, and at the same time the selected program is displayed on the preview image at step S386. This program is called a second program. At this step, video or audio information of the second program is displayed. In this case, the video information may be a moving image, a still image, and both of them. And, the still image may also be displayed in the form of a slideshow.

And, during a predetermined time after the program has been selected, the still image or slideshow-type still image is displayed. After a predetermined time has elapsed, moving images may be displayed as necessary. The preview-image display formats have been disclosed in FIGS. 36A˜36C.

The above step for storing channel information of the first program may be arranged until the EPG is displayed and at the same time the selected program is displayed on the preview image, after the EPG output selection signal has been entered. The above step for storing the channel information of the first program is irrelevant to the order between the EPG output selection signal entry time and the selected program output time.

If the output selection signal for the main image of a corresponding program from among preview output images associated with the selected program is selected at step S387, the selected program is set to a first program at step S388. Namely, the selected program is set to a program which will be received and displayed.

Thereafter, the EPG display is switched off at step S389, and the established new program is displayed as the first program.

A predetermined program title is not selected at step 387 after the preview image has been displayed on the screen. If an EPG-off signal is entered or a predetermined time elapses at step S390, the EPG output is switched off at step S391.

If a current mode is changed from the program guide output mode to the viewing mode, the broadcast receiver receives information of an originally-viewed channel using channel information of the first program indicative of the last output program of the stored viewing mode, and outputs the received information.

FIGS. 39A˜39C show EPG implementation examples according to another embodiment of the present invention. FIGS. 39A˜39C show embodiments of detailed information of the program list.

In one embodiment, an EPG control method for displaying detailed information of the program list receives an electronic program information of mobile service data, stores a program list and program detailed information corresponding to the program list, displays a program guide, receives a selection of a program list on the program guide, and outputs detailed information of the selected program.

In another embodiment, an EPG control method for displaying detailed information of the program list is as follows. The EPG control method receives electronic program information of mobile service data, stores detailed description of a program, requests detailed information of a program of a channel which is being viewed at a viewing mode, and displays detailed information of the requested program.

The above-mentioned steps will hereinafter be described.

The above step for receiving electronic program information of mobile service data, and storing a program list and its detailed information is as follows. At this step, a table including electronic program information of the mobile service data is received, the receiver receives a table equipped with electronic program information of mobile service data, stores information to be contained in the program list, and stores detailed information of the program.

If a user enters the EPG output selection signal on the condition that either the first program is displayed or mobile service data has no signal input, the EPG is displayed. In this case, the first program and the EPG may be displayed at the same time. Otherwise, the first program stops operation and only the EPG may be displayed.

At the above second step, a predetermined program title is selected by the user on the program guide at step S374. In this case, the selection signal can be entered in various ways. For example, if a cursor moves to a program title cell on the EPG, and a corresponding program title cell is highlighted, this condition may be considered that the selection signal has been entered. If a function selection key of a predetermined program title has been entered, this condition may be considered that the selection signal has been entered. The function selection of the predetermined program title is displayed on an option window, and a current-implementable function can be selected on the option window.

At the step for displaying detailed information of the selected program, detailed information of the selected program and the program guide are simultaneously or independently displayed. In this case, if program's detailed information is displayed at an area overlapped with the program guide, the overlay window may be configured in the form of a transparent window, so that the user can recognize even information located at the overlap area.

FIG. 39A shows program detailed information different from the program guide. FIG. 38B shows that the program detailed information and the program guide are simultaneously displayed. FIG. 39C shows program detailed information, which is divided into several steps.

Referring to FIG. 39A, detailed information of a program list is displayed at an area (i.e., an additional area) spaced apart from the program guide.

The above-mentioned operation that detailed information of the program list has been generated from the area spaced apart from the program guide is as follows. Namely, if detailed information of the program list is requested, the output of the program guide is switched off, detailed information of a program list is displayed on a new area. Otherwise, if program detailed information of a current-viewing program is requested when the user is viewing the program, program's detailed information may be displayed.

For the convenience of description, an area including detailed information of the program is called a program information box. In brief, an area on which detailed information is displayed is referred to as a program information box, irrespective of output format of program detailed information. And, the above-mentioned area where the detailed information is displayed is referred to as a program information box without considering whether the program detailed information is displayed at the same or different times as that of the program guide output time.

The program information box will hereinafter be described.

The program information box may include not only basic information of the program selected from the program list but also detailed information of the basic information. The present invention shows an embodiment of information capable of being contained in the program information box. In other words, the information cell may be optionally contained in a program information box. The selected program is selected by a user on the program list such that it is highlighted. Or, the selected program may be a default-highlighted program. The user's selection may be activated by the moving of a cursor or the selection of a touchscreen. Before the program guide is displayed, a program title, which is being provided to the user at a viewing mode, may be highlighted as a default.

The program information box includes a channel-information cell of the selected program. The channel-information cell may include at least one of a channel number or a channel name, and an input type. The input type may be a text type or a visual figure (icon).

The program information box includes a program title information cell of the selected program. The program title information cell displays a title of the selected program.

The program information box may include a program time information cell of the selected program. The program time information cell may include at least one of a start time, an end time, duration, a time progress bar, and a date of a program.

The program information box includes a current-time information cell. The current-time information cell indicates a current-date and time.

The program information box includes an image information cell of the selected program. The image information cell may display at least one of a moving image, a still image, or a slideshow-type still image of the selected program. In this case, the displayed image information may be extracted from the received electronic program information, or may be generated by a video signal received in the receiver.

The program information box includes a program status information cell of the selected program. The program status information cell indicates at least one of a setup function established for the selected program or a program character. In this case, the status information may be written in text or may also be denoted by a visual figure (icon).

For example, the status information may include at least one of reserved-recording information, reserved-viewing information, current-recording information, recording-completion information, Rx-sensitivity information, quality information (e.g., HD or SD), audio information (e.g., SRS or Dolby), multi-event information indicating a single event, series information indicating a series of programs, genre information, audience-rating information, pay TV, a rating level, copy-protection information, the presence or absence of caption, caption-language information, and audio language information.

The program information box includes a program detailed information cell. This program detailed information cell includes detailed explanation of program, additional information, and associated information. For example, the program detailed information cell may include a synopsis, characters, program planning, background knowledge or commodity information. In this case, the program detailed information cell may display commodity information or may enable the user to purchase desired commodities via two-way communication.

If a program guide is requested, and a specific program is selected from among the program list, the program information box is displayed for the selected program. Also, if program detailed information associated with a current-viewing program is requested while the user views the corresponding program, the program information box of the above current-viewing program may also be displayed as necessary.

In the above-mentioned embodiment, if the program detailed information is requested during the viewing time of the program, the program information box is displayed, and a program channel change occurs, the contents of the program information box can be changed to detailed information corresponding to the changed channel.

The above-mentioned program information box can also be equally applied to other types of embodiments of detailed description of the program list.

Referring to FIG. 39B, program detailed description and a program guide are simultaneously displayed.

The above-mentioned operation that the program list's detailed information and the program guide are simultaneously displayed is as follows. If detailed information of the program list is requested, the program information box may be displayed at an area which does not overlap with the program guide, or may also be displayed in the form of a pop-up type. In this case, the pop-up window may be displayed in the form of an overlay type indicating that the program guide overlaps with the output area. In this case, transparency of the overlay pop-up window is adjusted so that the adjusted pop-up window is displayed.

In this case, a detailed-information request signal of the program list can be entered in various ways. For example, if a cursor moves to a program title cell on the EPG, and a corresponding program title cell is highlighted, this condition may be considered that the selection signal has been entered. If a function selection key of a predetermined program title has been entered, this condition may be considered that the selection signal has been entered. The function selection of the predetermined program title is displayed on an option window, and a current-implementable function can be selected on the option window.

Detailed information of the program information box of FIG. 39B has been disclosed in FIG. 39A.

Referring to FIG. 39C, the program detailed information is divided into several steps and be then displayed,

A receiver receives program information of mobile service data, and the information display windows are classified according to several steps. Thereafter, the program detailed information request signal is sequentially configured. When a detailed information request signal is entered, program detailed information corresponding to the entered signal is displayed.

For example, the program detailed information is divided in two steps. Basic information of a program may be a first detailed information window, and additional information of the program may be a second detailed information window. Therefore, if the detailed information of the program is requested, the first detailed information window is displayed. Then, the detailed information is requested again, a second detailed information window may be displayed.

FIG. 40 is a flow chart illustrating a method for implementing details information of a program list according to the present invention.

A method for displaying a searching-start program highlighted when a program guide is displayed will hereinafter be described with reference to FIG. 40. For the convenience of description, if the program guide is displayed, a highlighted-start program from among the program list is called a start program.

If the program guide output signal is entered at step S4001, the start program is determined to be a current-viewing program at step S4002. The determined start program is highlighted, so that the program list is displayed at sep S4003.

The above-mentioned start program begins to search the program list at step S4004. If detailed information of the predetermined program is requested during the searching of the program list at step S4005, the program selected in the current searching is set to the start program at step S4006, the program-list displaying is switched off at step S4007. The program information box is displayed at step S4008, separately from the program list display.

If the program information box output OFF signal is entered while the program information box is displayed, or if a predetermined time elapses, the program information box is switched off at step S4010. If the program information box output is switched off, the start program established at step S4006 is highlighted on the program list, so that the program list is displayed at step S4011. If the program list is displayed, the program guide OFF signal is entered, or a predetermined time elapses at step S4012, the program guide is switched off at step S4013.

FIG. 41 shows EPG implementation according to another embodiment of the present invention. In FIG. 41. electronic program information of multi-sources received from the mobile service data receiver is merged, so that the merged result is a single program guide

A mobile hybrid source-signal receiver can receive mobile service data over the broadcast network, and can receive a program signal via several input sources (e.g., a satellite network, a mobile Internet network, and mobile communication network). The program information associated with the mobile service data can be received via the several input sources. In this case, if information of Rx-program information received via the several sources is merged so that the merged result is provided on a single program guide, the user can more conveniently select the program.

Referring to FIG. 41, the mobile hybrid source signal receiver according to the present invention further includes at least two source input modules and a source-integrated program information generator. The source-integrated program information generator merges at least two source input module with program information received from at least two source input modules, so that it outputs the integrated source program information.

The above-mentioned source input module, a mobile service data Rx module, a wireless Internet module, and a satellite Rx module, etc.

The source input module may be one of a mobile communication module, a mobile-service-data reception (Rx) module, a wireless Internet module, or a satellite Rx module. These examples have been disclosed for only illustrative purposes, the scope of the present invention may not be limited to only the above-mentioned examples.

The mobile hybrid source signal receiver includes a first source input module to an n-th source input module.

The source integrated program information generator 4120 integrates the program information received in the source input module 4110, so that it outputs the integrated source program information.

In this case, the source integrated program information generator 4120 integrates the program information received in the source input module 4110, so that it outputs the integrated source program information.

In this case, the source integrated program information generator 4120 assigns an identifier for identifying a source type to corresponding program information, so that different input signals can be distinguished from each other. Also, source information of the program information is extracted so that a source type can be discriminated.

FIGS. 42A˜42B show output views of integrated source program information according to the present invention.

Referring to FIG. 42A, in association with currently-received program information, information for identifying a source type and a program list information are displayed. In this case, the display format may be configured in the form of a general program guide.

Referring to FIG. 42B, program information of integrated sources is merged with each other, the merged result is displayed on a single program guide, and only program list information associated with an input source is activated. Namely, if the program information of the single source is displayed, and a user selects other sources, the program information of the selected source is displayed.

FIG. 43 is a conceptual diagram illustrating an EPG implementation according to another embodiment of the present invention. Program information and additional information are displayed on a single program guide.

Referring to FIG. 43, the electronic program guide (EPG) 4300 includes a program information area and an additional-information area 4320 other than program list information.

The program information area 4310 includes a program schedule and an explanation related with the program list. A method for implementing the program information area 4310 is applied to the present invention.

The additional-information area 4320 may display an advertisement image or advertisement text, or may also display advertisement-, news-, sports-, weather-, and stock-information.

The additional-information area 4320 may be color-coded or visually discriminated. The additional-information area 4320 may be located at strategic positions contained in the program guide 4300 to effectively draw the user's attention.

The advertisement image includes moving images or still images, or both of them. The still images may be displayed according to other display schemes (e.g., a slideshow scheme) at intervals of a predetermined time. The advertisement image includes all of advertisement messages to be open to the public, for example, commercial advertisement, public advertisement, missing-child advertisement, and movie advertisement messages.

The advertisement text may indicate a text-type advertisement message. All contents may be used as the advertisement messages.

The program advertisement may be advertisement messages of a currently-receiving program or the next program to be received in the future. If it is determined that an objective program is being broadcast now, the above-mentioned program advertisement may be tuned with the current-advertising program, or may be recorded with the same. If it is determined that an objective program is not being broadcast, when the program is broadcast, a user may be automatically tuned (i.e., reserved viewing) to the program, or may perform a reserved recording of the future program. The above-mentioned operations can be implemented by the additional-information area.

The news, sports, weather, and stock information may be received as information dedicated for the program guide. Data-broadcast image or text may be displayed on the additional-information area 4320. In this case, only the user's interest information may firstly be displayed on the additional-information area 4320.

The method for displaying the advertisement information according to an embodiment will hereinafter be described. Information displayed on the additional-information area will be described using advertisement information as an example.

FIGS. 44A˜44B show output views of details information of other information according to the present invention.

Referring to FIG. 44A, the program list information and advertisement information are displayed on an additional-information area. In this case, advertisement information is classified into a plurality of steps, brief information is displayed. If extended information is requested, more detailed information may be displayed on the additional-information area.

FIG. 44B shows an extended advertisement information associated with the brief advertisement information of FIG. 44A.

In more detail, a brief advertisement message is displayed on the program guide. If an extended advertisement is displayed by a user's request, the area size of the program guide can be effectively used.

In this case, the extended advertisement may include moving images, still images or text data.

In this case, all information of advertisement is received, this reception step is divided into several steps, a receiver may be designed to display the received information according to individual steps.

The receiver receives only brief information of advertisement messages, and displays the received information on the additional-information area. Upon receiving a request from the user, the receiver receives extended information of the selected advertisement, displays the received information, and output it. In this case, the receiver requires a two-way communication module.

As shown in FIGS. 45A and 45B, if extended information is requested for the advertisement information, a receiver is connected to an external server according to a two-way communication scheme.

Referring to FIG. 45A, the program list information is displayed on the program guide, and advertisement information is displayed on the additional-information area. In this case, if the extended information for the advertisement information is requested, the receiver is connected to the external server according to the two-way communication, as shown in FIG. 45B.

The two-way communication may be conducted over the Internet.

The external server may be a server of an advertisement-information provider, or a server (e.g., advertisement-object server) of an additional-service provider associated with advertisement information.

Namely, the receiver may access the advertisement provider's server, so that it can receive or search for more detailed extended information.

The receiver is connected to an advertiser's homepage, a shoppingmall Internet page, or an additional service-providing Internet page. For example, a user who carries the receiver views the advertisement of a corresponding product, and may directly buy the product from a shoppingmall Internet page according to a two-way communication scheme. Otherwise, the user views movie advertisement messages, and gains access to a movie-reservation Internet page according to two-way communication, so that the user may book a movie ticket via the movie-reservation Internet page.

The user's idea may be provided to the external server according to the two-way communication scheme. Namely, if the advertisement message is displayed, the receiver may transmit the user's purchase decision for a corresponding product, or may transmit any question to a seller or receive a response to the question from the seller. And, the user may request category information of a desired advertisement message.

FIG. 46 is a conceptual diagram illustrating an EPG implementation according to another embodiment of the present invention. FIG. 46 shows a variety of function call keys associated with the search of program list.

Referring to FIG. 46, the receiver does not fully search for the program list, may partially search for the program list. If the user desires to sort a program list according to a predetermined reference, the function call keys are displayed on the program guide.

The program guide 4600 displays a program list 4610 and a variety of function call keys (i.e., searching key 4620, filtering key 4630, and sorting key 4640). The function call keys have been disclosed for only illustrative purposes, and other function call keys associated with the program-list searching can also be displayed as necessary.

The searching cell 4620 provides a predetermined reference for all the program information, and displays program information including this reference. For example, if the user enters “

1

”, the receiver displays program information (e.g., a channel number, channel name, or program title) beginning with “

1

”. If the user enters “

”, the receiver displays program information (e.g., a channel number, channel name, program title) beginning with “

”.

In this case, reference data of the above searching may be entered by a remote-controller, or may be entered by a character input board, a touchscreen, or a video keyboard. Besides, all kinds of methods for allowing the user to enter a signal in the receiver can also be made available for the present invention.

For example, program information is classified according to categories (e.g., genre, broadcast viewing-date, rating-level). If a classification reference for each category is entered, the classification result is displayed.

The sorting cell 4640 sorts the program information on the program list according to a predetermined reference.

For example, if a reference (e.g., the orders of alphabets, capacities, durations, and popularities) is entered, the program information is sorted in the order of the entry reference.

FIG. 47 is a conceptual diagram illustrating an EPG implementation according to another embodiment of the present invention.

In FIG. 47, a viewing-restricted program (also called a “RRT” program) or a viewing-restricted channel (also called a “RRT channel”) is established, and a program guide is controlled by the established information.

Referring to FIG. 47, the EPG control method according to the present invention includes a first step for establishing a RRT (Rating Region Table) function; and a second step for controlling a display of the program guide information using the established RRT information.

For example, the channel 5-1 (4710) on the program list 4700 of FIG. 47 corresponds to a channel block object, and the channel 10-3 (4720) on the program list 4700 of FIG. 47 corresponds to a RRT program.

The above RRT establishing step includes: entering a RRT setup process (See FIG. 48A); and establishing a RRT level (See FIG. 48B).

The above RRT entering step may include a security step such as a password input function.

The above RRT-level establishing step may include a first step for establishing a RRT age or a second step for establishing a RRT channel.

In this case, the above first step for establishing the RRT age may be selected from the range of age established in the receiver, or may allow the user to enter his or her age. In this case, the range of age established in the receiver may be pre-established in a manufacturing process of the receiver. The classification reference of the age range may be changed according to broadcast transmitters. The age-range classification reference information is received and may be established in the receiver.

The above second step for controlling a display of the program guide information using the established RRT information includes: comparing the established RRT with a RRT age of program; and controlling the display of a program guide according to the comparison result.

In order to compare the established RRT with the RRT age of the program, the receiver must receive the established RRT information with the program's viewable-age.

The program's RRT age is processed as mobile service data, so that the receiver can receive the processed result via PSI/PSIP information. The receiver may extract the program's RRT information from a table including the RRT information in the PSI/PSIP information. In fact, the above table is a Rating Region Table (RRT).

The viewable-age information compared with the RRT age may also be established by the user. In this case, if the viewing-age information established by the user is different from the received age information, the receiver may enter a specific command for determining a predetermined age information to be a priority. For example, if the user-established viewable-age is prior to the received viewable-age, the established viewable age is compared with a predetermined RRT age.

The step for controlling the program guide according to the comparison result is as follows. If a program is determined to be the RRT program, it is not displayed on the program list, or a cursor may not move to a corresponding cell or may be deactivated. Also, the selection can be made available on the program list, but the output or display may be restricted.

The RRT information may be assigned to a recorded program during the recording of a corresponding program. If a corresponding recording program is reproduced, the RRT function may also be equally applied.

The method for controlling EPG information according to one embodiment of the present invention includes: registering a reference channel on a program guide; and shifting from the program guide to the registered preference-channel list output mode.

The method for controlling EPG information according to another embodiment of the present invention includes: registering a reference channel on a program guide; and constructing the program guide with the registered preference channel.

FIG. 49 is a conceptual diagram illustrating an EPG implementation associated with update of program information according to an embodiment of the present invention.

Referring to FIG. 49, if program information is received via an additional path (e.g., additional channel) different from that of mobile service data, a corresponding path is connected so that program information is updated.

The EPG control method according to the present invention includes: requesting the update of program information; and connecting a reception path of program information, and updating program information. In this case, if the update request of the program information occurs, information of the last channel currently provided to the user is stored. After updating the program information, a channel returns to the stored last channel.

If mobile service data is powered on, the display request of a program guide occurs, the update is requested at a specific time or is periodically requested, the program information update is requested at step S4901.

If the program information update is requested during the program viewing time, the last channel information is stored at step S4902.

The step for updating program information by connecting the Rx path of the program information is as follows. The receiver receives data of a dedicated channel via which program information is received, receives EPG data, so that it updates the conventional EPG data at step S4904.

The conventional EPG data is updated at step S4904. If received EPG data is determined to be a new-version EPG by comparing it with the conventional EPG data, the EPG can be updated. Otherwise, if EPG data is received, conventional EPG data can be compulsorily updated.

In the case of updating the conventional EPG data, only the changed program information may be updated or all the program information may be updated. If the program information is changed or updated, all cases (e.g., addition of new data, and correction of conventional data) are included. If only the changed program information is updated, the expired program information may be deleted as necessary.

When the receiver returns to the viewing mode after the EPG data has been updated, the receiver may receive again the current-viewing channel using the stored channel information at step S4902. If the receiver receives EPG update data using a redundant tuner at step S4903, the receiver may receive information of a channel tuned at a currently-used tuner at step 4905.

FIG. 50 is a conceptual diagram illustrating an EPG implementation associated with update of program information according to another embodiment of the present invention.

Referring to FIG. 50, mobile service data and program information may be updated.

The EPG control method of FIG. 50 includes: requesting a program information update; searching for at least one channel to collect EPG data; and updating conventional EPG data. In this case, if a program information update is requested under the program viewing mode, information of the last channel currently provided to the user is stored. After updating the program information, a channel returns to the stored last channel.

At a step in which the program information update is requested at step S5001, mobile service data is powered on, or update is requested at a specific time or is periodically requested.

If the program information update is requested during the program viewing time, the last channel information is stored at step S5002.

The receiver searches for at least one channel, searches for EPG data, collects program information of at least one channel, and updates conventional EPG data at step S5003.

In this case, the step for searching for the at least one channel may be implemented by searching for a single selected channel or all the received channels. Otherwise, the receiver may partially search for only a channel matched with a predetermined reference.

The conventional EPG data is updated at step S4904. If received EPG data is determined to be a new-version EPG by comparing it with the conventional EPG data, the EPG can be updated. Otherwise, if EPG data is received, conventional EPG data can be compulsorily updated.

In the case of updating the conventional EPG data, only the changed program information may be updated or all the program information may be updated. If the change of the program information is decided, all cases (e.g., addition of new data, and correction of conventional data) are included. If only the changed program information is updated, the expired program information may be deleted as necessary.

When the receiver returns to the viewing mode after the EPG data has been updated, the receiver may receive again the current-viewing channel using the stored channel information at step S5002. If the receiver receives EPG update data using a redundant tuner at step S5003, the receiver may receive information of a channel tuned at a currently-used tuner at step 5004.

It should be noted that most terminology disclosed in the present invention is defined in consideration of functions of the present invention, and can be differently determined according to intention of those skilled in the art or usual practices. Therefore, it is preferable that the above-mentioned terminology be understood on the basis of all contents disclosed in the present invention.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

As apparent from the above description, in the case of using the digital broadcast system and the data processing method according to the present invention, when mobile service data and mobile service data packet including PSI/PSIP information are transmitted over a channel, the digital broadcast system has very resistant to errors and is easily compatible with conventional receivers.

The digital broadcast system can normally receive mobile service data packet without any errors over a poor channel which has lots of ghosts and noises.

The digital broadcast system inserts known data at a specific location of a data zone, and performs signal transmission, thereby increasing the Rx performance under a high-variation channel environment.

The digital broadcast system multiplexes the mobile service data packet to main service data according to a burst structure, thereby reducing the power of Rx system.

The digital broadcast system can be more effectively used for mobile phones or mobile receivers, channel conditions of which are excessively changed and are weak resistances to noise.

The digital broadcast system can effectively provide the user with program-related information using the received PSI/PSIP information received with the increased Rx performance.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 

1. A method for receiving a broadcast signal, the method comprising: receiving a broadcast signal carrying a transmission frame, wherein a collection of data groups is carried within specific time periods in the transmission frame, each of the data groups including known data sequences, signaling information and mobile service data, which comprise broadcast service data for a mobile broadcast system, wherein each of the data groups includes: a first region in which the mobile service data is not multiplexed with main service data, a second region including a first data segment in which K bytes of the main service data are multiplexed with the mobile service data, and a third region including a second data segment in which M bytes of the main service data are multiplexed with the mobile service data, wherein K<M, wherein the first region is positioned between two regions of the second region and the first and second regions are positioned between two regions of the third region in each of the data groups, wherein the collection of data groups carries the mobile service data encoded through a Reed-Solomon (RS) frame, and wherein the signaling information includes an RS code mode for the RS frame; demodulating the received broadcast signal; building the RS frame including the mobile service data in the data groups and decoding the RS frame according to the RS code mode; extracting electronic program information about the mobile service data in the decoded RS frame; and displaying the extracted electronic program information.
 2. The method according to claim 1, wherein the receiving of the broadcast signal is implemented by selective reception of multiplexed main service data and the mobile service data.
 3. The method according to claim 1, wherein the receiving a broadcast signal includes: receiving main service data and the mobile service data within the specific time periods in which the mobile service data and main service data are multiplexed.
 4. The method according to claim 1, wherein demodulating the received broadcast signal includes: performing at least one of a carrier recovery and timing recovery on the received mobile service data using at least one known data sequence in the data groups.
 5. The method according to claim 1, wherein the demodulating step includes: compensating for channel distortion contained in the demodulated broadcast signal using at least one known data sequence in the data groups.
 6. The method according to claim 1, wherein the demodulating step includes: decoding the mobile service data in units of a block.
 7. The method according to claim 1, further comprising: storing the extracted electronic program information.
 8. The method according to claim 1, further comprising: configuring the extracted electronic program information in the form of a display format.
 9. The method according to claim 1, further comprising: receiving a user control signal; and controlling a display of the electronic program information by the received user control signal.
 10. The method according to claim 1, further comprising: receiving a user control signal; and controlling processing of the broadcast signal by the received user control signal.
 11. An apparatus for receiving a broadcast signal, the apparatus comprising: a signal receiving unit for receiving a broadcast signal carrying a transmission frame, wherein a collection of data groups is carried within specific time periods in the transmission frame, each of the data groups including known data sequences, signaling information and mobile service data, which comprise broadcast service data for a mobile broadcast system, wherein each of the data groups includes: a first region in which the mobile service data is not multiplexed with main service data, a second region including a first data segment in which K bytes of the main service data are multiplexed with the mobile service data, and a third region including a second data segment in which M bytes of the main service data are multiplexed with the mobile service data, wherein K<M, wherein the first region is positioned between two regions of the second region and the first and second regions are positioned between two regions of the third region in each of the data groups, wherein the collection of data groups carries the mobile service data encoded through a Reed-Solomon (RS) frame, and wherein the signaling information includes an RS code mode for the RS frame; a demodulating unit for demodulating the received broadcast signal; an RS frame decoder for building the RS frame including the mobile service data in the data groups and decoding the RS frame according to the RS code mode; a data decoder for extracting electronic program information about the mobile service data in the decoded RS frame; and an application controller for controlling a display of the extracted electronic program information.
 12. The apparatus according to claim 11, wherein the signal receiving unit receives main service data and the mobile service data within the specific time periods in which the mobile service data and main service data are multiplexed.
 13. The apparatus according to claim 11, wherein the demodulating unit includes: a known sequence detector for detecting the known data sequences in the data groups.
 14. The apparatus according to claim 11, wherein the demodulating unit includes: a demodulator which performs at least one of a carrier recovery and timing recovery on the received mobile service data using at least one known data sequence in the data groups.
 15. The apparatus according to claim 11, wherein the demodulating unit includes: a channel equalizer which compensates for channel distortion contained in the demodulated broadcast signal using at least one known data sequence in the data groups.
 16. The apparatus according to claim 11, wherein the demodulating unit includes: a block decoder which decodes the mobile service data in units of a block.
 17. The apparatus according to claim 11, wherein the data decoder extracts electronic program information about the mobile service data, and stores the extracted electronic program information to a PSI/PSIP database.
 18. A method for transmitting a broadcast signal, the method comprising: encoding mobile service data to build a Reed-Solomon (RS) frame according to an RS code mode; forming data groups of the mobile service data using separated portions from the RS frame, wherein each of the data groups include known data sequences, signaling information and the mobile service data, which comprise broadcast service data for a mobile broadcast system, wherein each of the data groups includes: a first region in which the mobile service data is not multiplexed with main service data, a second region including a first data segment in which K bytes of the main service data are multiplexed with the mobile service data, and a third region including a second data segment in which M bytes of the main service data are multiplexed with the mobile service data, wherein K<M, wherein the first region is positioned between two regions of the second region and the first and second regions are positioned between two regions of the third region in each of the data groups, wherein the signaling information includes the RS code mode for the RS frame; forming mobile data packets including data in the data groups; interleaving data in the formed mobile data packets; and transmitting the interleaved data via a broadcast signal carrying a transmission frame, wherein a collection of the data groups is carried within specific time periods in the transmission frame, wherein the collection of data groups carries the mobile service data encoded through the RS frame.
 19. A method for receiving a broadcast signal, the method comprising: receiving a broadcast signal carrying a transmission frame, wherein a collection of data groups is carried within specific time periods in the transmission frame, each of the data groups including known data sequences, signaling information and mobile service data, which comprise broadcast service data for a mobile broadcast system, wherein each of the data groups includes: a first region in which the mobile service data is not multiplexed with main service data, a second region including a first data segment in which K bytes of the main service data are multiplexed with the mobile service data, and a third region including a second data segment in which M bytes of the main service data are multiplexed with the mobile service data, wherein K<M, wherein the first region is positioned between two regions of the second region and the first and second regions are positioned between two regions of the third region in each of the data groups, wherein the collection of data groups carries the mobile service data encoded through a Reed-Solomon (RS) frame, and wherein the signaling information includes an RS code mode for the RS frame; demodulating the received broadcast signal; and building the RS frame including the mobile service data in the data groups and decoding the RS frame according to the RS code mode. 